Topic: r154 possible thrust issue?

[anticeptik]

Hi guys
i recently had my 2wd r154 rebuilt, a generic synchro and bearing kit was used, dritmotion billet forks 1-4, MC thrust washer, MC thrust bearing retainer and shifter rebuild kit.

I didnt personally rebuild it because i didnt have time, so im trying to diagnose the issue before i rip it out and take it back to the guy.
Basically when in neutral some power still transmits through the box, if the car is in the air the rear wheels spin very positively, engage the clutch it stops.
i can select every gear just fine, including reverse.

if the car is on the ground it will stay there but you can hear it labor up the engine and it wants to creep forward, but doesn't under the weight of the car
if the car is in the air, gear in natural, and your try to rotate the rear wheels by hand, its extremely difficult and rotates the motor, i played with all the gears in the air and narrowed it down to it spins as fast as 4th (hence 1:1 ratio) i feel like there's to much preload on it maybe?

the only thing when rebuilding the box which im sure it has nothing to do with, the synchros were different in-terms of engagement, the one that were in there were beveled and the ones i put in were dog tooth, but enagages the gears fine, so i don't think its that.

any ideas, i spoke to the guy and he said drive it around a bit and it should wear in, im not to keen on that, id rather not heat up the bearings or what ever if theres to much friction.

[71hornet6]

To make the R series the strongest during rebuild, I've heard it's best to use the largest c and u clips on the main shaft. They will fit to lock everything tight. Slop is the enemy of gears and wear increases exponentially as the slop increases with the gears. That's why when you build an axle, you have to set the right backlash so that there's room for oil and the gears won't get too hot from friction but not so much room that it makes it easier for the hammer action of stop and go to cause gear teeth to chip off.
It's possible he built it like this and you are experience binding before it's "broken in"
Another possibility is that you marred the pilot bushing a bit when installing your new transmission. I did this once. I was able to fix it by
-put the parking brake on
-push the clutch pedal down
-put the transmission into gear
-try and start the car
The starter tried to turn the flywheel, and the pilot tried to turn the input because it was binding. But since the transmission was in gear and locked via the back wheels, the starter was able to overcome the bit of binding in the bronze bushing and that fixed it.

It's worth trying as the starter will not produce anything near the amount of torque it would take to hurt your new transmission.