Blew out the OD gear today on my 65 C10 with Chevy Astro Van T5.
My guess it dropped a snap ring. Shifted into OD, gave it gas, pop and no overdrive.....no other noise and 1-4 + R continued to work fine.
On the T5 the OD gear is outside the case on the back end....Borg Warner did not design a new case when they switched from the T4 to the T5,,,,,they just stuck the OD gear on the back under the tail housing!
Just back from the workshop, confirmed it was a simple case of crapping the snap ring loose allowing the OD gear to slide back on the shaft where it couldn't be engaged..... and here's the fixes:
Expensive requires pulling the transmission down, machining a second snap ring groove, installing the Overdrive gear, 2 snap rings and a metal spacer between the two snap rings.
Less expensive and more often applied to the T5s in whatever make and model (Mustench, Camaro, Jeep, pretty much all the T5s have exhibited crapping of the OD Snap Ring) is to reinstall a new snap ring and give it three good tack welds. I went with tack welds. Its a low mileage rebuilt T5 in good condition and with normal care, I shouldn't have to open it up again for a long time.
Its nice to have 5 gears....but next time I'll install an automatic! (I wonder if a 4L60 will fit a 1965 L6 bell housing?.....)
Nice to see another T5 guy speaking up but sorry to hear that it gave you trouble. Sounds like you got it fixed in short order.
What OD gear do you have? What rear diff and tire size? I just installed a T5 in my 1965 C10 last night. Can't wait to drive it. It will be a while though.
