915 transmission – Third gear woes

Matt_West · 12-23-2007, 12:38 PM

Down shifting from 4th to 3rd expecting to match revs about 5K rpm; third gear refused to engage. Could feel a thrumming rotational energy through the shift lever. Aborted the step through 3rd gear; did my braking and hit 2nd gear. Transmission shifts normally except I can no longer select 3rd gear under any circumstances. No bad noises grinding or otherwise.

Tried shifting in parking lot at stop, clutch in and it won’t go. Tried letting out clutch and while pushing lever against third gear location with engine idling; felt thrumming but no engagement.

Tried shifting, clutch in and out, with engine off; no go.

Previously experienced similar intermittent balk shifting down to third at entrance to turn 2 at Pacific Raceways. Better matching of revs seemed to reduce the balk / amount of force required to complete the shift.

Transmission was assembled by local shop in the last 9 months, pretty much new everything. As built transmission is: fresh synchros, sliders, short gears (2nd – 5th), Guard limited slip, Wevo internal shift gate, PSJ, and shifter.

Oh Haha · 12-23-2007, 12:41 PM

Yikes, sounds like the synchro is gone. My 5th gear did the exact same thing last year. I would be contacting the repair shop that rebuilt the box ASAP.

Matt_West · 12-23-2007, 02:44 PM

Ugh..

Was hoping to not ever go back to the repair shop that did the transmission work again. Have had a real mix of service. The owner has been phenomal at times but there have been some definite misses that have led me to start a relationship with a new shop.

The shop that originally did the transmission rebuild, did it twice. The second effort was cited as necessary to a "failed" third gear I had supplied. I never felt quite comfortable with that explanation; but given that I had supplied the used part, I deferred to the shops expertise, good reputation, and friendly demeanor.

Suffice it to say that I have had two other instances where the shops service has not to meet my expectations and so I have decided to move on.

If there is anything I should verify short of an engine drop I will. Otherwise I will take it to the new shop for a proper diagnosis and repair.

Thanks,
Matt

Oh Haha · 03:19 PM

Do it yourself this time. I did my 5th gear rebuild. Granted, 5th gear is easy to access but once I got over the fear of digging into the box itself, I was ok and will rebuild it myself in the future.

Do a search here for tips and help. Except for a couple of special tools and maybe a local shop for a press, you can do it. Heck, there is probably a Pelican or two that live close to you that would assist.

I'm not sure what you mean by a "failed" third gear but if you supplied them with a used set, there isn't much you could have done. Was the last gearset they installed new?

Steve@Rennsport · 12-23-2007, 03:16 PM

Quote:

Originally Posted by Matt_West

Ugh..If there is anything I should verify short of an engine drop I will. Otherwise I will take it to the new shop for a proper diagnosis and repair.

Thanks,
Matt

Hi Matt:

IMHO, based on your experiences, thats the wisest course of action.

Matt_West · 12-24-2007, 05:21 AM

Decided to try and drive it home and investigate linkage. In second gear under light load at about 4500 rpm, there was a pop noise after which the selector was stuck in 2nd gear. Drove two miles at 35mph to safe location with phone.

Car has been towed to trusted shop.

Oh Haha · 12-24-2007, 05:24 AM

Keep us posted on the outcome, Matt.

spuggy · 12-25-2007, 06:12 AM

Matt, that's awful - sorry to hear it. At least it didn't explode... Hope it works out..

BTW, could you PM me the names of the two shops involved? I noticed you were careful not to name them publicly.

I'll be on the Eastside again in a month, and I'd sure like to avoid the first one...

Matt_West · 12-29-2007, 02:16 PM

Fluid has been drained. Chunks of metal confirm carnage awaits when the case is openned. Will update with details when I have them.

Matt_West · 01-07-2008, 04:54 PM

Good news here. The owner of a company that manufactured some parts which are in my transmission read the above post. He sent me an email mentioning that his records indicated he had supplied some parts and was interested in the details.

Shop tore down the box and identified some failed parts. Analysis cannot determine the cause of failure; only that the OE dog teeth pressed onto third gear were no longer seated all the way. Parts were sent to supplier and while the cause of failure has not been determined the damaged / out of spec parts have been replaced free of charge.

Current shop and suppliers assessment is that the transmission was correctly assemble the last time around.

Needless to say I am a very happy customer and am extremely pleased with the level of service provided. For my part I will forever be a customer and will recommend their product when appropriate.

Oh Haha · 01-07-2008, 06:08 PM

Maybe mention the name now that they provided good service?

Matt_West · 01-07-2008, 06:40 PM

While I feel it was extrordinary service and worthy of applause. The manufacture monitors the site and I leave it to them to identify themselves and take a bow if they desire. Kudos for standing behind the product.

Jim Sims · 01-07-2008, 07:26 PM

A thread that may be interest:

Welding on dog teeth?