I took it apart and thought I might see something obviously wrong but didn't notice anything crazy. Here are my symptoms: It's hard to shift into every gear and some gears you have to put pressure to get them in. There's two distinct noises, the first is constant and only goes away when the clutch is pressed (assuming this is the input or main shaft bearings). It is a very loud whine like a drill. The second is louder when there's a load on the trans and gets quieter in 4th gear. 5th and reverse are a fight to get into gear and there's loud slop heard with hollow banging sounds when ever trying to shift. I think the trans may have just been beaten very hard. There doesn't seem to be any evidence it wasn't just not changing the oil or water or rust in side the case. No evidence of broken parts and the synchros and gears don't have any obvious wear...

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This is a 99 4runner trans, and rebuild kits are hard to come by, has anyone located a source for the kits?

I might try to see if a ax-15 trans rebuild kit would work. Any other advice? The only thing that struck me as odd is a lot of play in the mainshaft. the bearing in the center piece seems to allow it to move alot more than I would expect..

I think I might just need a bearing kit. The synchros don't seem too worn but I'm not sure how to tell...

Marlin has a bearing kit for it

Here are my symptoms: It's hard to shift into every gear and some gears you have to put pressure to get them in.
Typically I've found that Toyota transmission are a bit harder shifting compared to other manufacturers. Redline MT90 gear oil usually helps for easier shifting...

There's two distinct noises, the first is constant and only goes away when the clutch is pressed (assuming this is the input or main shaft bearings). It is a very loud whine like a drill.
Sounds like a bad throw out bearing

The second is louder when there's a load on the trans and gets quieter in 4th gear. 5th and reverse are a fight to get into gear and there's loud slop heard with hollow banging sounds when ever trying to shift.
Getting quiet in 4th is normal since all the load is taken off the gear train 1:1 ratio, power transfers directly through the shafts...

Just wondering if your clutch isn't disengaging completely??? this could cause hard shifting as well... Hollow banging sound, did you check your driveshaft?

I think the trans may have just been beaten very hard. There doesn't seem to be any evidence it wasn't just not changing the oil or water or rust in side the case. No evidence of broken parts and the synchros and gears don't have any obvious wear...

The synchros don't seem too worn but I'm not sure how to tell...

If the trans was beaten hard as in forced into each gear, the odds are your syncros and shift forks are worn and probably won't be so obvious unless you tear it completely down. Since you have it that far apart, might as well replace them....

Marlin is the man when it comes to rebuilding trannies

This is a junkyard trans with unknown history. The problem is definetly not outside the trans itself in the clutch or anything as all parts are new. For example, shifting the trans on the bench with no clucth or anything connected is ROUGH.

I think you are right and it may have just been abused and shifted hard, and that I should do a bearing replacement and check all the clearances for out of spec readings.

I know Marlin has a bearing kit for these trans but I'd like to find it for under $739 considering I could get a junkyard trans with a warranty for $500....

Bruce, when I say hollow banging sound I mean when shifting when sitting with the engine off. Its like a hollow thud like if you were to hit the side of the aluminum case with something. It really sounds as if there are missing c-clips and the front input bearing is banging against the bearing retainer when shifting. It is an internal noise... I checked for missing components and worn out bearing lands in the aluminum case and everything seems relatively tigt and intact. No hollowed out bearing holders in the aluminum cases.

The play in the main shaft is likely the reason its hard to get into gears. This is a common problem on this trans. Marlin sells new main shaft bearing retainer to help solve/prevent it. The other solution is to shim the bearing so that it does not move.

Your first noise sounds like a clutch prob, not a tranny one. Did the noise go away with slight pressure on the clutch pedal, only when fully depressed. If so, probably just the release bearing needing replacement and/or the bearing slightly rubbing on the fingers.

The other noise may just be bearing noise. It could be bad bearings or it could be a symptom of the main shaft play/misalignment.

This article might help:
http://www.4x4wire.com/toyota/tech/r151f/

I need to tear down my T100 trans as soon as I get my Runner done and have something else to drive. I don't have noise but the shifting is difficult sometimes and it grinds going into 5th unless I shift really slow. Pretty sure its the main shaft play.

Hey Erik thanks for the response. The clutch should be ruled out as I know it's adjusted properly and its all new parts. The noises are present UNLESS I press the clutch so it is an internal transmission problem.

I just removed the input, main, and coutershafts and going through the FSM instructions to check for out of spec measurements. I will pay close attention to the stamped steel bearing retainer.

So far I have only checked the input shaft bearing and synchro, and it is fine. Next is the output shaft assembly...

Funny you just posted this as I am in the market for a rebuild kit for my Turbo trans. Marlin wants a hefty $429 for the Turbo trans kit!

I found some Post 95' rebuild kit's:
www.importdrivetrain.com
4 Runner, T100 Truck Tacoma Truck all V6's Bearing Overhaul Rebuild Kit
$ 267.20 -OR-
http://www.drivetrain.com/toyotaR150rwd.html
K100517 With 59mm Outer Diameter Rear Mainshaft Bearing 1995-97 $287.27

This trans appears to be in perfect shape. The synchros I can access without breaking down the output shaft, first and fifth, still have the ridges in them, they look brand new. None of the bearings have any play in them.

The only thing that seems strange is the pocket bearing for the input shaft, if i put the two shafts together without the synchro and spin them against each other there is a bit of noise. However there is no wear evident in the needle bearing itself or in both races. I'm not sure if that's just a noisy bearing to begin with.

All clearances are within spec, gear thrust spacing, shift forks, and synchro spacing. I ordered a dial indicator to check radial clearance on all the gears. Any other suggestions?

your problem is frighteningly similar to what my 98' r150F tranny is doing. when driving it has a howl to it. its subtle enough you may throw it out as harmonics noise. but due to the hard shifting, resisting to fall into gear, makes me wonder. if i slow my shifting it seems to help but other times im stuck. have you replaced all the bearings, synchros and tried out the results yet? would like to hear that you have had success so i can go and have the same. thanks for your post!

Check the shifter bushing too. If its broken apart it could give you hard shifting.

There's two distinct noises, the first is constant and only goes away when the clutch is pressed (assuming this is the input or main shaft bearings). It is a very loud whine like a drill. The second is louder when there's a load on the trans and gets quieter in 4th gear.

So what ever came of this? My trans has the same symptoms. Marlin has a 10-week turn-around time right now, so it's time to explore other options.