Rebuilt transmission… broken during smog check?

[BrokeMyCar]

Hi folks,

About a decade ago, with much help from this forum, I rebuilt gears 1-2 of my 915 transmission. Happy driving ensued, though of course not as much as I’d like until the kids got a little older. This week I took it in for a smog check and afterwards the transmission felt totally different. It wouldn’t settle into 1st, just move the stick up and then the car would shudder and stall. It wasn’t like the gear was rejected, or ground while it went into gear. By cycling through gears I could regain that satisfying settle into first and it would grab and drive well. Until I had to get into first again… It’s bad enough that I couldn’t get into gear at a couple intersections.

I’m thinking of starting with draining the transmission fluid to look for damaged parts. I don’t really have the time luxury of re-rebuilding the transmission (see: kids). Any other ideas of things to look for or try?

Thanks-

[rwest]

I would open up the cover on the tunnel in the backseat area and see if the coupler bushings have disintegrated. Also check the two bushings near the shifter before tearing into the transmission.

[Bill Douglas]

I'd talk to the smog check people first and try to get them to pay. As soon as you touch it they could claim it's your fault.

[ErrorMargin]

I’d also bet on failed shift coupler bushings. It is really unlikely that the smog guys could do damage that would cause that behavior.

It takes just two minutes to check the bushings and all you need is a Phillips screwdriver. You can open the cover and check for the bushings without disturbing anything, so there is no risk of them saying that your checking the bushings caused the failure.

[porsche930dude]

Also check the ball and socket bushing at the bottom of the shifter. If you used regular petroleum based grease on the bushings they disintegrate much faster.

[EC900]

Not sure what type of smog check they do in CA but if they drove the car to the service lane, or if they run up speed on a dyno. maybe it was the techs lack of knowledge with the shifter more or less jammed the old brittle bushings to oblivion ?
Last time you changed out the nylon shift bushings and/or coupler? Clutch condition?
Can that “shuddering” seem like kind of a wrong gear engagement - which can point to failed bushings or coupler throwing off the 1-3 shift plane due to the slop.
If possible, pull up boot and peer thru the inspection hole on the side of the shift tower you should get a quick idea if shift rod bushing is gone.

[BrokeMyCar]

This is great advice, I totally wasn’t thinking of the linkage. I’ll inspect it over the next couple of days and hopefully post pictures too. Thank you!

[winders]

Originally Posted by Bill Douglas

I'd talk to the smog check people first and try to get them to pay. As soon as you touch it they could claim it's your fault.

Good luck with that....

[BrokeMyCar]

Wow, great advice folks. I think we have a clue in the back-seat coupler... new bushings ordered.

[yelcab1]

So, it was not the smog guys fault that some people were so quick to jump to? The newest 915 transmission is ... 1986, so it's 37 years old. You bring a 37 years old car to a shop and anything that goes wrong is their fault?

[ErrorMargin]

Originally Posted by BrokeMyCar

Wow, great advice folks. I think we have a clue in the back-seat coupler...

Make sure to replace all the bushings. You need this kit:

https://www.pelicanparts.com/More_Info/PELBUSHKIT1N.htm?pn=PEL-BUSHKIT1N&bc=c&SVSVSI=0581

[BrokeMyCar]

Bushing replaced, and wow I wish I did this earlier. All the remnants of the hard plastic bushings were in the boot around the coupling. Thanks all!