IIRC that endplay would be decided by the roller race under that bearing. Did you change any bearing parts or gear? I am pretty sure you dont want that to be loosely tightened.

9 minutes ago, Dave WM said:

IIRC that endplay would be decided by the roller race under that bearing. Did you change any bearing parts or gear? I am pretty sure you dont want that to be loosely tightened.

I reused the old "overdrive gear bushing" but used new needle bearings in between. If the old one was "too short" in length, it could cause this issue right?

 

 

I was on my thinking throne earlier today and remembered this tool from Autozone to change out tie rods. It has a die for both 1-1/2, and 38.4mm. Worked great, didn’t have to make anything custom.

When you say "the end play goes super tight and out of spec...." you mean no clearance at all?

It is good to read you are checking clearances. Some people don't and it can destroy what could have otherwise been a very good rebuild.

No clearance: That is not good at all. You need clearance between the gear and end washer to lubricate the needle bearing and end faces of the gear or the gear will litterally weld itself to the washer, hub and damage the needle bearings beyond use. The problem is without enough clearance the needle bearing starves of oil and overheats. The gear will then expand faster than the other components and create more friction/heat. The extra friction will weld it to the washer or hub, trust me.

 

1 hour ago, EuroDat said:

When you say "the end play goes super tight and out of spec...." you mean no clearance at all?

It is good to read you are checking clearances. Some people don't and it can destroy what could have otherwise been a very good rebuild.

No clearance: That is not good at all. You need clearance between the gear and end washer to lubricate the needle bearing and end faces of the gear or the gear will litterally weld itself to the washer, hub and damage the needle bearings beyond use. The problem is without enough clearance the needle bearing starves of oil and overheats. The gear will then expand faster than the other components and create more friction/heat. The extra friction will weld it to the washer or hub, trust me.

 

@EuroDat I torqued the main nut to 110ft-lbs the clearance is around 0.25mm on the 5th gear. That’s 0.05 tighter than OEM spec.

 

oh so its not locked, that's good. could be a tolerance stacking up issue with the new bearing. If it was me I would mic out the old bearing and compare to the new, maybe even just reinstall and check again to see if old bearing gives you clearance per spec. If so and new bearing is indeed larger (unlikely but if) then i suppose you could get a flat stone and carefully sand down the washer. better to mill it but that may not be practical. I know I had a hard time finding that inner race, i had to  order from japan, I did not like the idea of a new bearing on an old race.

Edited July 31, 20222 yr by Dave WM

8 hours ago, heyitsrama said:

@EuroDat I torqued the main nut to 110ft-lbs the clearance is around 0.25mm on the 5th gear. That’s 0.05 tighter than OEM spec.

 

0.25 is OK. You will not have any problems with that clearance if you use a good quality oil like MT-90.

6 hours ago, Dave WM said:

oh so its not locked, that's good. could be a tolerance stacking up issue with the new bearing. If it was me I would mic out the old bearing and compare to the new, maybe even just reinstall and check again to see if old bearing gives you clearance per spec. If so and new bearing is indeed larger (unlikely but if) then i suppose you could get a flat stone and carefully sand down the washer. better to mill it but that may not be practical. I know I had a hard time finding that inner race, i had to  order from japan, I did not like the idea of a new bearing on an old race.

dumb on my part about thinning the washer that would do nothing...

I was at my desk this morning, and it looks like the older 1980 gearboxes have a tighter tolerance than the “close ratio” 81-83 boxes. I’m not sure what gearbox this is anymore, it had a  RHD main shaft, but a CR tail housing…. It’s a mix. I think I’m happy with the end play at the moment, everything seems to be in “spec” 

@Dave WM thanks for your YouTube videos BTW, I’ve been using them as a reference.

@EuroDat I’ve been really happy with the MT-90, I’m got some fresh stuff for this rebuild. But to be honest the old stuff is so clean I’ll probably use it in my beater. 

On a side note, I thought about safety wiring these roll pins, to avoid any “lost shifters” at the track. I don’t know how I feel about the “looseness” of the wire, and it wearing down the aluminum shifter forks…. Am I just thinking too much about it?

I’m not 100% on the shifter fork orientation for 1/2 gear. I saw an old photo that @Patcon posted and I think it’s right… no image in my phone or in the manual…

It looks pretty good, the housings are washed up. Hopefully I can get it buttoned up tonight, and installed tomorrow after work. 

Pretty sure that I've read about doubling up on the roll pins.  Pin in a pin.

Turns out that you can buy them that way too.  Also, coiled spring pins.

https://www.jackstransmissions.com/my-cart/store-home/double-roll-pin

https://www.grainger.com/category/fasteners/pins/spring-pins

 

20 hours ago, heyitsrama said:

I’m not 100% on the shifter fork orientation for 1/2 gear. I saw an old photo that @Patcon posted and I think it’s right… no image in my phone or in the manual…

It's in the right way. It wont fit the other way. The other end where the selector rod passes through colides with 3rd and 4th when you fit the fork on backwards.

If you feel comfortable wiring the forks it shouldn't do any harm. I take it you want to wire them because you're worried they might fall out or work their way out. They shouln't fall out that easy.

I have only ever seen two 71B with them double pinned like @Zed Head said. One was for a rally car and the other was unknown.

So I assembled the front/tail housing over the assembly (with sealant) and started researching how to check the clearance between the front counter bearing and the housing.

Its hard for me to get a precise measurement on the bearing, When I measure the top (between the front mainshaft bearing) its 3.20-3.7mm depending on the spot I measure it, on other areas its between 3.12-3.2mm... I might be able to use the old shim (0.4mm) but I might have messed up....

I noticed this post by @Dave WM

I failed to consider the dimples on the thrust washer when i assembled the 1/2 gears, so its a 50% chance that I assembled it correctly... I don't like it. I'm probably going to pull it apart again to double check the orientation, I assume these dimples are to allow oiling on the bearing, and I'd rather do it now then again....

Is disassembly a destructive operation on the bearings? I read that you don't want to create a load on the outer race of the bearings. The disassembly process seems is stressing the bearings (esp when you have to beat the mainshaft/counter shafts out...)

I don't mind doing the work over again, its probably going to go way faster this time.