Topic: First time diagnosing a tranny problem

[bkubisht]

I tried this on pirate a few days ago, but got no love...   I really need to spend more time here and less time there.

I had an '85 W56A (aluminum center) and 4th gear growled terribly and others also somewhat so I pulled it when I did a motor swap. I bought an unknown year/mileage W56B (steel center) for $50 that had a cracked tail housing, and swapped the W56A housing onto it. Two problems were obvious from the first time I drove it.

First and foremost, it sounds like a bearing whines when there's no load on it above 30mph. In any gear or neutral, cluch engaged or not. If I accel or decel at least a little it quiets fine. So I'm thinking it's one of the bearings on the output shaft, based on staring at the FSM diagram a bit. I'm afraid of pulling it apart and not being able to tell visually. And if it's one I can change without pressing the whole assembly apart I'd like to know that in advance, since I have to rent access to a press. Is there some test I can do to narrow this down better before I tear into it? The same 4.7 tcase was used with the two transmissions, so I'm pretty sure it's not in the tcase.

Secondly, 3rd gear is tricky to get into. I can hit it nearly every time if I first jump in&out of 4th. The syncros are fine on all the other gears, so I'm doubting that only the one on 3rd would be worn. After driving it daily for a couple weeks, I just figured out that if I push the stick up toward 3rd, then apply pressure leftward, I can get straight into 3rd without grinding or anything. It's a perfect touch thing, pretty hard to get right every time. Is this related to the first problem?

[79coyotefrg]

dude,  that second tranny  is as bad as your first tranny,
it desperately needs a rebuild

i would say  send them both to marlin  for a cores  on a new tranny  you'll never have to worry about again

[BUDDERS]

It sounds like the pinion bearing is toast as well as the 3rd gear syncro.  Did you take repeated stabs trying to get that belhousing to center up on the block when you installed it?  This could have possibly damaged the pinion bearing in the end of the crank - as far as I can tell, that's the only thing that is still spinning with the clutch engaged or not.

Just out of curiosity, what do the shifter bushings look like?

[bkubisht [OP]]

The shifter bushing was still intact, although I have a new marlin one waiting to go in.  The shift pattern isn't sloppy at all.  Good suggestion though, I'll change it before dropping the tranny just to be sure that's not 3rd gear problem.

Pinion bearing... you mean the pilot bearing?  I'm pretty sure that's not it because the noise can be duplicated with the clutch engaged.  Same reason rules out the throwout bearing.

I'm definitely going to scrutinize the 3rd gear synchro, gear, and corresponding teeth on the counter gear once it's apart.

Fresh marlin tranny does sound nice, but it's not in the budget at this point.  I'd like to learn more about it anyway because the transmission is the only part of these trucks I haven't worked on yet.  I think I would understand and respect the transmission a lot more if I did it myself.  If a full rebuild is where this heads, don't worry.  Marlin is the only source I trust for the rebuild kit.

[BUDDERS]

Yeah, it was the pilot bearing I was thinking about, not the pinion - that one is waaay different.  Does the noise happen with the truck stationary with the clutch engaged and dissengaged?  If so, the pilot bearing still sounds suspect, and mabye even the input bearing on the trans..  I just replaced a trans on my buddies celica and that was the same problem. 

The 3rd gear syncro still sounds suspect, so it looks like you will have to rip the trans out anyway.  Tear it apart and see what you find.  I bet when you drain the gear oil out of it, there would be a lot of metalic particles in it from the syncro.  Those transmissions are not scary to pull the case apart on.  Once you've split the case open, just leave everything attatched to the  center support and put it in a vice.  Start turning it and manually move the shifter forks and you should see the problem.  Pay special attention to noises coming from bearings.  If they are in the least bit suspect, now is the time to replace them.

[Willy Mammoth]

I would have a complete rebuild kit handy when tearing it apart. That way you have all the bearings syncros seals and gaskets needed to put it back together right once.

Also keep your old one handy for parts if they are the same.

I bet you will find the bearings worn, maybe even the cages coming apart.

[highridin4x4]

Does it pop out of third gear if you step on the gas the let off of it. It could be the center support bearing having play in it from being worn out.

Here are some pictures of my worn out bearings the first pic the center race is pushed in and the second pic is the center race pushed out. with this much play my main shaft was moving front to back and making it hard to get into gear and it would pop out some times.





And here is one of the wear itself on the race(the input bearing would make a growling noise when the tranny was spilling only with the clutch pushed in there was no noise at all).



Hope this helps

Scott

[Goose]

Fun stuff transmissions are...
Sounds like the same problem Ive been having, but Ive got an r150
4th and 5th gear have a nice screaming whine to it when cruising or coasting,
under load it quiets down...

I suspect bearings, and im sure the tranny's long due for a rebuild..
For now i got a another tranny to swap into it, while i rebuild the screamer

[bkubisht [OP]]

It doesn't pop out of gear at all, once it's there it's strong.

I've decided how to proceed, based on the FSM.  The first tranny had an awful lot of gear oil buildup in the bellhousing, so I'm thinking the 4th gear growl was due to a bad bearing on the input side, likely the input bearing itself.  I'll pull it apart this weekend, and if that isn't the obvious problem then I'll rebuild tranny #2 including synchros.

If I end up doing the full rebuild, I assume I'll need a shop press.  I'll use the tool loaner program for bearing pullers from autozoo as necessary.  I've got caliper, feeler guages, dial indicator, torque wrench, and some good snapring pliers.  Should I budget for any other tools?

[Goose]

beer?   

[BUDDERS]

A healthy batch of rags, parts cleaner, and red fipg from Toyota to be used as a gasket material when putting it all together.  Don't use permatex, it's crap compared to toyota silicone.  I also second beer 

[bkubisht [OP]]

Budders, would you believe I've still got one more tube of the black stuff from when you gave me a bunch years ago?

[BUDDERS]

Yup, I would, but I'd still use the RED toyota FIPG - its made for this aplication and the black stuff is not.