Transmission Break-In Period

[nene]

What has been your experience upon having a refreshed 915 Tranny in regards to shifiting?

I recently had mine refreshed from 1-4, and find that some at points it is just
difficult to shift. I understand that they need to be broken it, but Jezuz!



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[Reiver]

Old parts mixed with new parts.
I had my 915 refreshed about 2 years ago and it shifted ok but a bit 'hard'...and occasionally balked going into 2nd. It took a good 1k miles to be just right.
No issues now.

[jeffbottman]

My 1-2 rebuild shifted like butter from the get-go. But then, Mr. Walker did the work ... what more need I say ...

[OsoMoore]

I did 1st and 2nd gear synchros + blocks, 1st gear dog teeth, and 1st/2nd shift sleeve. A year later and about 1500 or so miles, it shifts better than ever (although 2nd still requires a pause on the way in).

I'd say it was about ~500 before I stopped noticing the "new surface wear" feeling.

[midnight911]

new dogs, syncros for 1 to 4, GT turbo carrier upgrades, etc, and GT LSD. went easy for the first 2000 miles, changed oil. feeling good ever since.

[pmax]

Hard to believe the transmission needs such a long (1000 mile) break-in period.

[Reiver]

Originally Posted by pmax

Hard to believe the transmission needs such a long (1000 mile) break-in period.

Lots of 915's with different mileage/history. Mine had 246k miles on it when 'refreshed' and I've no idea what was done prior.
It works smoothly presently but did take a bit to mate old/new surfaces it seemed.
After that period no issues.
I suspect a full rebuild where everything is tolerance checked and all parts replaced would be a different gig.....I replaced what was broken (lost dog teeth) and a few other worn items.

[gliding_serpent]

Mine frlt great after 500 miles, but never frlt that bad post rebuild. This is sll subjective and I am sure everyone has different expectations however.

[gomezoneill]

I just rebuilt my transmission and engine. After install I could not get the transmission to shift at all, then I kept trying back and forth through all the gears then it started to shift slowly into the gears. After driving 50 miles or so the transmission shifts smoothly into all the gears now like new. I replaced all the syncros sliders and dog teeth along with the pinion bearing repair. I needed to adjust the shift linkage a few times to make it right.

[john walker's workshop]

There's an installed diameter +/- on the syncro rings. Too big and they shift hard. GL5 gear oil recommended, not the blue stuff.

[nene]

Thank you all for the feedback!


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