My Hoopty

[kentwat]

Congrats on the rebuild and the swap. It always makes me feel proud when I know I'm the one that rebuilt it. As for start up I just always park it in Neutral and use the E Brake. Post up some fresh pics showing off your accomplishments. Kent

[Oldblueaccord]

It's really nice to have my red car back. I missed her terribly. The tranny is having some issues that are probably the result of using two trannies to create one by cherry-picking parts from each. It will probably take a long time for all the mismatched parts to wear together again and stop being so fussy.

I still need to wire up the cruise control and I'd really like to have the clutch interlock. I've been driving an auto for so long, there's a high probability that I'll end up rearranging the front end some morning when I go to start it up. I park behind the Bimmer, so I'll get a twofer if that happens.

Put it in neutral when you start it anyway. Less wear on the thrust bearing on the crank with the clutch out on start up.

wp

[Dr_Snooz]

Well, I suck. The tranny is screwed. It's shifting better, but started making a most horrible growling today. When I take off from lights, it's like ggggggrrrrrrrRRRRRRRROOOOOOOWWWWWWWWLLLL!!!!!! <shift> ggggggrrrrrrrRRRRRRRROOOOOOOWWWWWWWWLLLL!!!!!! <shift>

It made a Pling! Clunk and the growling improved slightly so stuff is flinging itself apart inside there. Not sure what I screwed up, but I'll have to pull it and see what's left of it all.

This is my first manual rebuild. My first auto rebuild was a bust too. I put it in and it made the most ungodly clattering and blew fluid out the underside of the car to the tune of a quart every few days. Pulled it out and found that I had not seated an alignment pin properly between the block and bell housing. It bent over and got munged between the two. It put the tranny out of alignment just enough to make the drive plate bolts hit the block. It pinched and damaged the main seal too and allowed fluid to escape. Oh God was it loud and a tremendous mess. I got to throw away the drive plate on that one.

I threw the tranny away too. It was a three-speed that did 4,000 rpm at 75 mph. A four speed swap was available, so I rebuilt the four-speed and popped it in. It worked great and brought the revs down to 3,000 at 75. I loved that car ('82 Accord).

I'll let you know what I figure out.

Good grief.

[Civic Accord Honda]

Damn man that really sucks , You never learn unless you try tho

[nswst8]

School of hard knocks, I know it well. Don't give up. If I were closer I'd lend a hand.

Good luck

[89T]

you know i had issues with a bent shift assembly, grinding and growling especially 3rd gear.I ran out of ideas on how or what needed to be replaced. By chance i swapped the out assembly and it runs fine now.

It seems like you're going to toss what you have now for another, but i thought i would share.

[Dr_Snooz]

you know i had issues with a bent shift assembly, grinding and growling especially 3rd gear.I ran out of ideas on how or what needed to be replaced. By chance i swapped the out assembly and it runs fine now.

It seems like you're going to toss what you have now for another, but i thought i would share.

I appreciate the sharing. Thank you. I will definitely open the trans up to see what's going on. I'll check out the shift assembly first though.

[89T]

Thanks, I don't know if it will fix you'r problem, but info is alway's a good thing.
good luck!

[Dr_Snooz]

This is a long post, but well worth the read.

I performed the post-mortem today. There was a LOT of metal in the oil I drained. Everything was assembled correctly but I have another destroyed mainshaft. That makes two transmissions in my shop now with the SAME broken part. I apologize for these pics. Half of the lights are out in the shop and I couldn't get the pics lit well enough to prevent them from smearing. Here's what the mainshaft looks like:



Here's the trans:



It's hard to see, but several teeth have been sheared clean off the mainshaft. The breaks are very smooth and very clean. There's no evidence of grinding or chewing or anything else. You can see in the pic that the teeth that are left are perfect. No gouging or messy-ness of any kind. This gear does not change position, so it wasn't destroyed by power shifting or crappy syncros or gear-grinding, etc.

Okay, so

I'm a little uncertain what did happen, but I have a hypothesis. My original transmission had a destroyed mainshaft. The reverse gear was missing most of its teeth. They had been gear-ground to oblivion, so I bought a second transmission. After disassembling that one, I had double parts. I carefully selected the best parts from each transmission to build this one. I thought I was being very clever, but I now think that was a mistake. After 200,000 miles, the parts in each transmission had very distinct and very different wear patterns. When I swapped them around, the differing wear patterns did not mesh cleanly and I had gear whine, difficulty shifting and finally, another destroyed mainshaft.

When I was putting the main case on, I had to squeeze the two shafts together to get them to fit through the holes. I thought it just needed some rotation to get things meshed together, but I now think that it was the different wear patterns between those two gears not fitting together. When I forced the shafts together, it put severe stress on those teeth at the bottom end of the mainshaft and eventually popped them off.

It's not the first time I've seen this kind of thing. When I was in high school, I rode my bike everywhere. Every summer, I would faithfully tear down all the bearings, clean them up and re-grease them. It always worked great. It was a very old bike and probably had German or American bearings. Years later when I got a bike with Japanese bearings, I did the same thing that first summer and everything went wrong. It was like the bearings had all turned square. The wheels didn't roll and I couldn't get even tension on the bearings. I came to find out that the bearing cups were not perfectly round. They were slightly oblong from the factory. They weren't off enough to cause problems with the original wheel, but over time, the ball bearings wore to some other shape than spherical. When I pulled them out and rearranged them, it all went to crap. I replaced the old ball bearings with new ones and was rolling again just fine.

Anyway, that's my hypothesis. Let me know what you guys think.

[lostforawhile]

ouch the sight of amputated transmission parts makes me queasy! i'll have to look in my book, but i think you have to assemble the main and countershafts assembled as a unit, are you missing any thrust washers? there are a bunch of end play clearances that need to be checked with a feeler gauge, did you check those?

[Bass Man]

Yep, gears are married and don't like to swing around after 20 years!! haha...

That sucks, man... Should get a teggy tranny and build that!

[Dr_Snooz]

ouch the sight of amputated transmission parts makes me queasy! i'll have to look in my book, but i think you have to assemble the main and countershafts assembled as a unit, are you missing any thrust washers? there are a bunch of end play clearances that need to be checked with a feeler gauge, did you check those?

I'm pretty careful with my builds. I checked as many clearances and tolerances as were practical and wrote them all down in the manual. There were a few parts that were borderline or slightly out of spec, but nothing wildly, gear-shearingly out of spec. I did check both the thrust washers I had for thickness (the same on each) before selecting the one and putting it in.

I followed the manual closely for the assembly and stopped every so often to make sure everything was feeling right. There were no red flags or anything that felt off or not right. That's what has me so perplexed on this build. Usually when something blows up, I know exactly what it was. There was that part that didn't look right, or the bolt that didn't feel right as I was torquing it or that point where I shoved something together that wasn't fitting. This time, I have nothing. Everything was done right. That's why I'm thinking it was the mis-matched parts.

[Ichiban]

Wow. That sucks. The only thing I could see causing that is excessive backlash. And backlash is set by adjusting the center distance of mating gears. In your case, center distance is dictated by the bearing bore spacing, and not adjustable, the only other factor affecting center distance would be clearances in the bearings. Since you replaced all the bearings, this theory goes out the window.

Since the gear looks like the teeth were chewed off towards the top of the small gear (opposite the bearings side) is it possible that the mating shaft is missing a part, causing the large gear to ride too far up and overloading the edge of the gear, rather than riding in line with it? When you tighten the locknuts at the end of the transmission, they actually draw both of those shafts upwards and slightly away from the bearings in the bellhousing. Those end bearings behind 5th gear are what actually axially locate the shafts. Something wrong with either of those gear stacks could allow one to be misaligned from the other. Did one shaft end have a bunch more thread exposed than the other when it was assembled?

Just throwing out stuff here.

[ecogabriel]

This is a long post, but well worth the read.


It's hard to see, but several teeth have been sheared clean off the mainshaft. The breaks are very smooth and very clean. There's no evidence of grinding or chewing or anything else. You can see in the pic that the teeth that are left are perfect. No gouging or messy-ness of any kind. This gear does not change position, so it wasn't destroyed by power shifting or crappy syncros or gear-grinding, etc.

Okay, so

I'm a little uncertain what did happen, but I have a hypothesis. My original transmission had a destroyed mainshaft. The reverse gear was missing most of its teeth. They had been gear-ground to oblivion, so I bought a second transmission. After disassembling that one, I had double parts. I carefully selected the best parts from each transmission to build this one. I thought I was being very clever, but I now think that was a mistake. After 200,000 miles, the parts in each transmission had very distinct and very different wear patterns. When I swapped them around, the differing wear patterns did not mesh cleanly and I had gear whine, difficulty shifting and finally, another destroyed mainshaft.

When I was putting the main case on, I had to squeeze the two shafts together to get them to fit through the holes. I thought it just needed some rotation to get things meshed together, but I now think that it was the different wear patterns between those two gears not fitting together. When I forced the shafts together, it put severe stress on those teeth at the bottom end of the mainshaft and eventually popped them off.

Wow this sucks!!!

I do not really see the "cherry picking" of parts as the worst problem. Parts have to be machined very precisely in order to make them fit with another gear when doing the initial assembly in the factory. I remember watching on TV how they assemble auto trans and the operator picked each gear from a box without any particular order other than the required by the assembly itself

True, some whining noise will be present after mating say a new gear with an older one, or like here where two different (used) ones were employed. But proper machining (which is done with this kind of gear stuff) should not cause self-destruction. Incidentally, my dad knew how to make gears and told me about this several times (he did repair work involving machining gears) so he would make all the necessary parts new (if possible) to avoid noise. But he also told me about how the machining (and the materials) for automotive applications were done differently than the regular stuff he would make (in his day anyway).

So I am not really into believing your pick and choose was the problem. I would instead think on the transmission case.

Did you use the original case (the one that blew the reverse) or the second transmission case you got?
The fact that you had to squeeze the shafts together to fit them into the case is telling that center distances between gears was off.
If the shafts were, say bent then in certain positions they would be so tight and in others so loose.

Sorry for the long post. Bottom line: I would take a look at the case. I have heard of transmissions blowing themselves up due to misaligned/defective cases; not factory-defective but perhaps over time (and abuse) a case may deform in slight ways.

Another suggestion would be placing the shafts on a lathe to check for off-center. Lost will know better about this as he knows his way around a lathe.
My 0.02...

[ecogabriel]

Thinking on the trans case, I was thinking on why that particular gear exploded and not any of the other ones. The answer: gear ratios

Say the gear ratio between the destroyed one and the larger one is 3:1. That means the small one turns three times in order for the large one to turn one time. This meas that teeth in the small gear work three times more often than those in the large gear which explains why they blew themselves up first.

I would bet that they broke the way they did because the part that broke off was the first one to see "load" when turning

In reality, gear ratios are never exact because otherwise the same teeth in the small gear will work with the same teeth in the large one. when the ratio is not exact (say, 3.29:1) each teeth works with all the others in the other gear thus minimizing the formation of wear patterns.

[Ichiban]

Thinking on the trans case, I was thinking on why that particular gear exploded and not any of the other ones. The answer: gear ratios

Say the gear ratio between the destroyed one and the larger one is 3:1. That means the small one turns three times in order for the large one to turn one time. This meas that teeth in the small gear work three times more often than those in the large gear which explains why they blew themselves up first.

I would bet that they broke the way they did because the part that broke off was the first one to see "load" when turning

In reality, gear ratios are never exact because otherwise the same teeth in the small gear will work with the same teeth in the large one. when the ratio is not exact (say, 3.29:1) each teeth works with all the others in the other gear thus minimizing the formation of wear patterns.

Wow this sucks!!!

I do not really see the "cherry picking" of parts as the worst problem. Parts have to be machined very precisely in order to make them fit with another gear when doing the initial assembly in the factory. I remember watching on TV how they assemble auto trans and the operator picked each gear from a box without any particular order other than the required by the assembly itself

True, some whining noise will be present after mating say a new gear with an older one, or like here where two different (used) ones were employed. But proper machining (which is done with this kind of gear stuff) should not cause self-destruction. Incidentally, my dad knew how to make gears and told me about this several times (he did repair work involving machining gears) so he would make all the necessary parts new (if possible) to avoid noise. But he also told me about how the machining (and the materials) for automotive applications were done differently than the regular stuff he would make (in his day anyway).

So I am not really into believing your pick and choose was the problem. I would instead think on the transmission case.

Did you use the original case (the one that blew the reverse) or the second transmission case you got?
The fact that you had to squeeze the shafts together to fit them into the case is telling that center distances between gears was off.
If the shafts were, say bent then in certain positions they would be so tight and in others so loose.

Sorry for the long post. Bottom line: I would take a look at the case. I have heard of transmissions blowing themselves up due to misaligned/defective cases; not factory-defective but perhaps over time (and abuse) a case may deform in slight ways.

Another suggestion would be placing the shafts on a lathe to check for off-center. Lost will know better about this as he knows his way around a lathe.
My 0.02...

You've got some great points here, some that I forgot to mention in my original post, and a couple I might differ with. You are exactly right in assuming the smaller gear sees more wear than the larger one will. In applications where there is an extreme difference in mating gear surface speeds, such as worm drives, you will often see different materials being used for each gear. For example, a hardened steel worm being mated to a phosphor bronze worm wheel.

However, in terms of load, the larger gear will always have more. Remember that the small gear always turns faster, at the expense of torque.

I also agree that the "worn in together" aspect of the cherry picking parts issue is not the problem. Automotive gears are generated, hardened, ground and finally lapped to exacting tolerances. Sure one box might wear a bit different than another one, but stick them together, they'll whine and run hot for a while, but eventually simmer down.

I do disagree that the cases may be a contributing factor. In terms of being distorted, at least. .005" of deformation in a bearing bore would cause obvious signs of, well obliteration. Also, these tiny Honda box's are no where near long enough to twist or sag like large castings can. Enough deflection to cause problems would simply shatter the case.

Here's something I didn't think of before: Remember how Honda likes to change little shit?

-Suppose they changed the pressure angle or module of those gears sometime between 83-89, or whenever those parts could have possibly been made? Mating gears MUST have the same pressure angle and module (or DP for standard gears) Pressure angle in simple terms relates to the shape of the involute curve of the gear tooth, while module and diametral pitch refer to the actual size of the gear tooth, using a roundabout method of # of teeth/pitch diameter or vice versa.

What if a gear spec change was subtle enough that you didn't notice on assembly? I kinda doubt it though.

-Also suppose Honda did something stupid like made a gear .03" thinner, and a spacer .03" longer. I already know that the bearing actually pressed into the bellhousing came in different sizes, I had to machine a .079" thick spacer to make my only salvageable bearing fit. Any number of things could have changed. If there were a change like this it could affect the length/position of your shafts once the locknuts were tightened down.

Also, checking shaft runout on a lathe between centers is simple. All of those shafts are center drilled, simply mount a center in the lathe spindle, stick the shaft in, and ram the tailstock center up its ass. Then check for runout with a dial indicator on any of the ground bearing surfaces. Make sure the part spins when you turn the headstock, or of course it will read 0 runout.

By the way, how hard did you have to squeeze these shafts together to get them to fit? Gears have to have a certain amount of clearance and backlash, or they WILL fuck out. My case went together without any squeezing whatsoever.

[Dr_Snooz]

I had to squeeze pretty good. Probably around an 1/8". Enough that if a few revolutions didn't loosen it up, then with heat and load, that pressure would be enough to pop teeth off a gear. Especially if the gear bearing the brunt of it was a little one acting as a fulcrum on the very end of the mainshaft. That does indeed look like what happened.

I'm also not liking my mix and match hypothesis. If anything, those parts should get sloppier over time, not tighter. So that's rubbish.

Areas for further inquiry that I'm gathering from your posts are the following:

1. Look for missing thrust washers. There are two. One on the mainshaft and another on the countershaft.
2. Bent mainshaft. Should be easy enough to check.
3. Bent case. Should be easy to measure the distance between the two shaft bearings in each case. The case didn't leak, so it can't be too far off
4. Figure out why I had to squeeze those shafts together. This is probably the most likely and I'm not sure how to tackle it.

One other thought: I managed to overtorque the mainshaft lock nut quite dreadfully as I was assembling. I thought I had a torque wrench that clicks in the reverse direction, so I was torquing with all my might when I realized that I don't. I backed off the nut and re-torqued to my best guess of 65 ft-lbs. I don't think that really did anything in this case, but it's a thought.

Thanks so much for the feedback. I appreciate when the smart guys here weigh in on the stuff I've managed to screw up. It helps me learn.

[2oodoor]

snooz says..."i like to take hammers, and just break stuff, just break stuff."

:d

[lostforawhile]

BUTHEAD IT BLEW UP !! IT'S THE COOLEST THING I'VE EVER SEEN!!
I figured you might need some comic relief

[Dr_Snooz]

:d

[ecogabriel]

You've got some great points here, some that I forgot to mention in my original post, and a couple I might differ with. You are exactly right in assuming the smaller gear sees more wear than the larger one will.

However, in terms of load, the larger gear will always have more. Remember that the small gear always turns faster, at the expense of torque.

I also agree that the "worn in together" aspect of the cherry picking parts issue is not the problem. Automotive gears are generated, hardened, ground and finally lapped to exacting tolerances. Sure one box might wear a bit different than another one, but stick them together, they'll whine and run hot for a while, but eventually simmer down.

I do disagree that the cases may be a contributing factor. In terms of being distorted, at least. .005" of deformation in a bearing bore would cause obvious signs of, well obliteration. Also, these tiny Honda box's are no where near long enough to twist or sag like large castings can. Enough deflection to cause problems would simply shatter the case.

Here's something I didn't think of before: Remember how Honda likes to change little shit?

-Suppose they changed the pressure angle or module of those gears sometime between 83-89, or whenever those parts could have possibly been made? Mating gears MUST have the same pressure angle and module (or DP for standard gears)

What if a gear spec change was subtle enough that you didn't notice on assembly? I kinda doubt it though.

-Also suppose Honda did something stupid like made a gear .03" thinner, and a spacer .03" longer. I already know that the bearing actually pressed into the bellhousing came in different sizes, I had to machine a .079" thick spacer to make my only salvageable bearing fit. Any number of things could have changed. If there were a change like this it could affect the length/position of your shafts once the locknuts were tightened down.

Also, checking shaft runout on a lathe between centers is simple. All of those shafts are center drilled, simply mount a center in the lathe spindle, stick the shaft in, and ram the tailstock center up its ass. Then check for runout with a dial indicator on any of the ground bearing surfaces. Make sure the part spins when you turn the headstock, or of course it will read 0 runout.

The issue of a change in specifications crossed my mind after posting; maybe the only way to check is with a parts number catalog.

We are assuming in this discussion that what was in the boxes was OE Honda parts. Maybe it was not the case; if any box had seen a repair shop before it may have received its gearing from a third party source. In that case, any slightly off specification parts would not cause a problem because both were cut the same way. When "mixed and matched", the harmony (and the transmission) broke

[lostforawhile]

I can tell you who to contact, call Mantrans in Tallahassee Fl, they are expert manual re builders, they also can get any part you need. they work through the mail too. A lot of people at Panhandle gear heads used to use them. http://www.mantrans.com/?q=node/1 they have a good rep around here

[Dr_Snooz]

I can tell you who to contact, call Mantrans in Tallahassee Fl, they are expert manual re builders, they also can get any part you need. they work through the mail too. A lot of people at Panhandle gear heads used to use them. http://www.mantrans.com/?q=node/1 they have a good rep around here

Thanks for this. I'll give them a call and see what they think. It's so hard to find trustworthy shops.

I ran my pictures past an airplane mechanic buddy at work today. He suggested "sudden stoppage" (ie: a crash) as the culprit. He thinks that the trans came to an abrupt stop and stress fractured those gear teeth. He thinks the shafts didn't align because they were bent. When I put the bent shaft back in the box and started using it, those stress-fractured teeth gave up first. I noticed a lot of vibration after the swap, indicating a bent something. That explanation makes the most sense so far.

It should be really easy to see if the shaft is bent. I'll just rig the two halves of case together to hold the shaft (I don't have a lathe) and then spin it. It will have to wait till this weekend though.

Best thing to happen all day: the tranny is still under warranty. I just have to take it in and wait for them to ship the replacement. Woohoo!

Stay tuned for more.

[lostforawhile]

I think you are right, if the transmission stopped as in a wreck, the old one you got parts from, it would have put a lot of load on those teeth, and possibly bent the shaft, if the transmission suddenly stopped all the load of the car will be transferred to those teeth through the differential

[Civic Accord Honda]

even tho i didn't want to come on here much anymore i still like to check threads and thought i would post in this one,

I was just wondering if both transmissions were from LX-is, and had the same gearbox number(someone could of swapped in with a DX/LX one in a lxi at one point) and the DX/LX one has diffrent gear ratios then the LX-i one so was just thinking maybe that could be a problem why the gears didnt fit right