Tranny (465) gurus - cant get third....

[mtweller]

Well, got the swap done and went for a test drive today. History - fresh rebuild on 465 (my first tranny rebuild btw) and passed my bench test. I was able to find all gears and turn the shaft.

So I have 1st, 2nd, 4th and R with only one issue, cant find 2nd until almost a complete stop. Tranny will go into third (at least feels that way), but when I put a load on it (ie let the clutch out) it grinds immediately and pops out. I can't hold it in either.

FYI - I did not replace the shift forks or rebuild the top end (shift rails). I did take the shifter out and use a screwdriver to engage 3rd w/ same results.

PLEASE tell me I just need a new shift fork. At least I can trailer and trailride w/ 1st and 2nd and R

Thanks in advance for any help.

 

[Straightjacket]

Did you use a complete rebuild kit? If your shifter forks are not bent then it's probably a spacing issue. Detents in wrong,snapring came off? Just did my first also,so I'm no expert,just trying to help.

 

[mtweller]

No snapring issues I'm sure, I installed the 3rd gear snapring elimination spacer. And, I bench tested it so I thought I confirmed the shift / gear spacing was correct. Plus, how could only 3rd be an issue since the other gears work? Hmmm, sure hope I don't have to pull this beast!

 

[jcj_78FJ40]

Is it possible that you missed a shift collar with one of the forks when you put the top on?

 

[mtweller]

I'll have to look at a schematic to see if that is a possibility. But, it does "try" to engage the gear, it just kicks it back out as if it only engages 1/2 way or less. thanks for the ideas guys

 

[Straightjacket]

You said you engaged the gear with a screwdriver,and it still came out? I assume you had the top off? If you did have the top off did it fully engauge? If it did how does the gear look,does it have good dogs on it? What about the metal bushings,were they replaced? Can't remember if third had a replaceable bushing? My kit didn't come with them,had to be purchased seperately.If it pops out with the top off that shouldn't be the issue.Detents should be the only thing left. Your making me nervous,mine bench tested fine.Sure hope it works!

 

[mtweller]

No, the top was still on. I was not clear, sorry. I used a srewdriver to engage the shift rails the the shift lever out. IOW, the ship rail seemed to move the proper amount verified by removing the shift lever and using a long screwdriver to move the shift rails.

 

[Straightjacket]

Well it sounds like you need to pull the top and inspect the tranny.It's pretty much the only way to know for sure whats up. Then you could take some pics and someone would probably be able to tell you for sure. With the top off you could engauge by hand and be sure it fully engauges,and detents lock. You could also pull a side plate and make sure none of the needle bearings came out on install.Away

 

[jcj_78FJ40]

You might also check in the Chevy forum on Pirate.

I learned that the shifter mechanisms in the top plate can be problematic. Are you using the SM465 gear shift? I have read that if the welds are broken on the end, there could be issues.

I did the same swap a few months ago and used a shifter from a LC 3 spd. Everything works well except for that I get a loud clunk when I push in the clutch under load. I haven’t had time to track down the cause yet. I may be pulling mine back out also.

Good luck!

 

[mtweller]

Update:

Took Dozer on a trailride...man I love that gearing. Almost immediately, the tranny started roaring, like metal on metal, but did not feel any binding. Just as I thought, after tearing it down, I confirmed first gear is contacting the rear of the case. The rear gearset on the mainshaft will move forward about 1/8" and slide backwards as well. Does this mean I missed a spacer? Orrrr, is there supposed to be something tight against that rear bearing in the case to keep it from moving backwards? When we built the adapter plate, we clearanced for that bearing, so there is no pressure on the shoulder to hold it in place. Copule of pictures attached below:


As far as third gear, did I put the shift collar on backwards? with the cover off, there are no issues moving the collar solidly into third gear. Pictures attached.

Thanks to all!

 

[mtweller]

3rd/4th shift collar:

 

[Pin_Head]

Maybe you forgot the thrust washer that goes between first gear and the rear main shaft bearing? It is part #19 in this pdf of the service manual:
http://www.kinzers.com/don/landcruiser/transmissions/sm465/doc/300x300/sm465.pdf

Maybe this allows the shaft to move rearward enough to prevent 3rd gear engagement? The shift sleeve orientation looks proper.

 

[mtweller]

No, the first time I assembled, I forgot that washer, but tore it back down. I am thinking there needs to be pressure on that rear bearing that is translated to that thrust washer - thoughts?

Thanks for the idea Pinhead!

 

[Pin_Head]

Main shaft lock nut missing or backed off?


Rear main shaft bearing backed out?

Wrong thrust washer (too thin)?

Anyway, this is way too much thrust play for a constant mesh gear.

 

[jcj_78FJ40]

It may be that the rear bearing is not fully seated. I would try removing the rear bearing retainer, wedging something between the granny gear and the front of the case and then giving the rear bearing a good couple of wacks with a hammer and a piece of pipe. The torque spec for the bearing retainer is 100 ft/lbs.

To pin_heads point, you might also check the thrust washer while you are doing it. The thrust washer that came with my Novak kit was larger in diameter and was interfering with the outer race of the rear bearing. I ended up using the one that was originally in the transmission. I later noticed that the Novak washer was machined down on the outer edge so I probably just had it in backwards.

 

[mtweller]

Well, I'm going to drain the t-case and pull it soon. Further troubleshooting to come, but I would LOVE it if I didn't have to pull this monster! Thanks for the help fellas.

 

[Straightjacket]

It's a bummer to have to pull something like that back out. I've had to take mine in and out a couple of times.I had to do it by myself,so I slung it from the roll cage and used a comalong to lower,it was a piece of cake! I also used a ratchet strap,and a tiedown once also pretty easy.It's harder to deal with the transfer. Please keep us informed of what you find.
You'll need a couple!

 

[mtweller]

So after scratching my head, I need to confirm this:

The rear portion of the mainshaft and gear assmembly is held into the case ONLY by the friction of the rear main bearing in the case - correct??? If that is the case, that is my problem. That bearing moves in the case "fairly easily". In other words, when tightening the bolts on the front bearing retainer, the rear bearing would slide rearward until the 1st speed gear contacted the cae. I then reseated the rear bearing, which created the correct spacing b/w the 1st gear and case.

If that is the case, it seems to me I need somehow to make that bearing stay put! Ideas????

The bearings were all replaced, so I know that isn't the issue (unless the rebuild kit is less than perfect). How would that cast case lose that much tolerance? Maybe the bearing seized on the shaft at some point in its life and bored out the case???

 

[Pin_Head]

The adapter plate retains the bearing and prevents it from moving out of the case.

 

[jcj_78FJ40]

The adapter plate retains the bearing and prevents it from moving out of the case.

X2

Make sure the rear bearing outer snapring is in place. Install / tighten the rear bearing retainer and bolt on the adapter plate and see if your problems go away.



My replacement bearings were the same way.