rebuilt transmission miles for 1st change?

[mike sampsel]

Have 930 miles on my rebuilt 915 transmission.

What is better mileage to change, 1000 or 1500? Or does it make a difference?

Syncros and dog teath were changed along with some other parts. In the rebuild.

[yelcab1]

Call me an optimist but I don't think I would change it until you have driven it 15,000 miles. It's just gear and synchros. If you cleaned it really well during assembly, what's to wear?

Now, if you are like some owners who only drive their cars sparingly, then every two years swap the gear oil out.

[GH85Carrera]

No matter how well you cleaned, there is always some debris left behind. 1,500 miles is a good time to do it. The oil is cheap, many orders of magnitude cheaper than just one scored bearing.

And order a drain plug with the magnet in it. Use that one in place of the fill hole. Keep the magnetic drain plug in place. The differential throws oil right on the side of the transmission where that fill plug is. Any crap generated will get captured by the new fill plug.

[cassisrot]

Post a pic if you have any.

[mike sampsel]

Originally Posted by cassisrot

Post a pic if you have any.

What are you interested in seeing?

[chrismorse]

I just had CMS go through my 74 box, Guard LSD, side plate, teddy bear, bearings, synchro, sliders, bore repairs, 4th gear, new r&p, Wevo shift gate.
Roger recommended Swepco and to change it at 1000 miles, so I ordered up a few gallons to take care of that eye wateringly expensive bit of my dad's car.
I just paid more for the box repair/upgrade than my dad paid for the whole car brand new in 74. Another $100 for a gallon of swepco ??
Cheap insurance.
Chris

[G450X]

915 parts are very expensive now - my 915 rebuild cost more than my nice used SC did.

I have 10k in a spare 915 I built with short 2nd thru 5th gear sets for my SC. I went with a Wavetrac for traction to save some money because costs were spiraling out of control.

I also added a Wevo internal gateshift, CMS one piece bearing retainer and reinforced side cover with a 930 bearing “while my tech was in there.” The chassis has a Rennshift an Stomski PSJ to help prevent a dumb shift on my end.

At least my R&P and other internals were good...

[chrismorse]

Glenn, great tip on the fill plug, will do.

Mike, I admire that paint, color and condition, cripes, it is spotless underneath!!!!

With the "goodies", the tab was $13.5K
Hope never to need to do it again, my Dad never had the box worked on, about 175K miles, for reference. Plus, he was a very "moderate" driver.
I plan on annual gear oil changes.
Good luck,
Chris

[nene]

I was told by my P-Car mechanic that rebuilt my 915 that there was no need to change it right away.