84 Pickup, 5 speed manual SR5 4X4

Hey guys im getting ready to have the tranny rebuilt and t case rebuilt with a 4.70 gear kit...ive been call around to get some quotes and a gentleman who came highly recommended was telling me that when he was done with my tranny that the best thing to do is run 10-30 synthetic motor oil in it...

now ive never heard of running motor oil in the tranny before, ive always ran gear oil cause its OEM. he told me it would help with the stiffness of shifting..to me it would seem like it would never allow the syncros to break in.. any thoughts

Second, with the 4.70 low range gear kit installed will be ok to run the stock tranny mount (the rubber one from the tranny to x-member) or will the added torque cause problems..i know they sell stronger mounts but a buddy has one and the vibration that comes thru is baaad.

this is a hunting truck/Daily driver.

any thoughts or advice?

 

Anyone have any thoughts on the motor oil in the tranny...anyone done it, pros?...cons?

just gunna run the stock mount and if she breaks upgrade later.

 

Motor oil is designed for a motor. Not a manual transmission. Use a good quality gear oil, there are plenty of oil threads out there.

 

Some Hondas use engine oil in the trannies.

Run Redline MT90 in your trans though. And find another rebuilder... If he is recommending engine oil, he doesn't know what he is doing.

The aftermarket poly mount will give you all the vibes. Rubber is softer so it won't transmit everything. But it will break more often...

 

GL4 only for my Toyota. If you go to napa and they sell you GL5 and try to tell you its the same its not. GL5 has everything GL4 does but has more in it than whats needed. Meaning it burns out sycros faster.

 

The only benefit he said it gave was an easier shift. I've always ran gl4 geAr oil I don't mind the" hard shifting". If I'm shelling out the money to have these rebuilt I want it to last. 200+K on the old one running gear oil.. think I'll stick oem spec.