Freshened 915 & Seine upgrade = Happy Shifting

[jjeffries]

Hello All,

I'd posted a couple of years ago about the difficult 2nd gear in my then-new-to-me 82 SC with 185K miles. On about 50% of shifts into second, whether up or down, the gear would baulk....I had to double or triple pump the lever to get into 2nd. The other 50% of shifts were perfect. At first I'd though it was heat related, but that proved not to be true. I changed the gear oil with Kendall, adjusted the shift rod, confirmed it had recent bushings, checked the dongle-fork, made sure the clutch adjustment was good....just about everything short of the pulling the transaxle apart.

I read Peter Z's tutorial and Gordo's thread and came to the conclusion that while I'd rebuilt the engine, working on the 915 wasn't for me; I saw too much need for discretionary decision making that needed an expert eye, and didn't want to under-or over-repair the unit. So I dropped the motor/trans in January and took the latter to Automobile Associates in Canton, Connecticut, about 45 minutes from where I lived. We agreed that they'd just tackle the problem at hand and leave the rest alone; they replaced 1st and 2nd synchros, dog/teeth rings and the 1-2 slider. Locals know that AA is an excellent shop and awfully nice guys to boot. Their repair - I'm not calling it an overhaul - cost ca. $1400 (YMMV/$$ based on what's found on teardown). I got the old parts back and saw the teeth on the 2nd gear dog ring were pretty beat. ALL 2nd gear shifts were now crisp and predictable, what a transformation.

I'd bought a Seine kit to install once the gearbox itself was repaired, and worked on that last weekend but waited until today to drive it...we still have snow here. The installation was straightforward. I think it's a clever design, the parts are nicely made and I enjoy the proverbial "rifle bolt" action. I'd also say that anyone who asks of the Seine kit "$150 for a couple of plates and a spring?" is foolhardy: there's more to it than that, including the engineering. I couldn't afford a JWEST or WEVO shifter assembly and consider the Seine a great value precisely because it retains the standard shifter assembly yet solves its flaws.

I'm pleased with the results and am posting about it because "915 shifting problems" are such a common discussion here that I wanted to share my outcome. Best, John in CT.

[Driven97]

Great to hear. How about first? My car will occasionally take 2 tries to get into first, and I have to be <5mph before attempting it at all. 2nd is usually ok, just have to, as I describe to others, "ask nicely and wait for permission."

[jjeffries]

Driven, first wasn't terrible before, but it's better now. Before it would slip happily into first from second while the car was moving, even from something like 15mph, but it could be a pig to get into first while the car was stationary. Thus, you always planned to get into first before ariving at a stop sign or red light, but that meant a lot of time standing on the clutch as you waited for the light to go green. Now it still goes into first on the move but can at rest. John

[Duc Hunter]

Great to hear. My 915 shifts like crap. PO had it rebuilt buy a "reputable" shop in Ga. They replaced the synchro's, dog rings, and synchro brakes. 1st and 2nd are often impossible to push into gear without a double clutch, and when you do they then drop right in. 3rd on are buttery smooth. It is like the gate is closed. The synchros never make any grinding so I know they are fine.

My mechanic here, who builds 901 and 915 tranny's for race cars, says they clearly used new sycro brakes. He showed me on some old parts that the brake is what I feel as it snaps into gear (or does not). He says the new synchro brakes that everyone uses are just way too stiff, especially when used with new synchro's. He tries not to put new brakes with new synchro's, its one or the other. He reuses the old ones if they are good, and collects old ones that can work. His conclusion on mine is drive it, they will eventually brake in....in a few years.

I assume yours goes right into gear no issue, etc? Did they replace your synchro's and synchro brakes?

[GaryR]

I'm amazed that you got a 915 touched for $1400!! I know Scott at AA, great guys..

[911pcars]

I must inject my regular suggestion (rant) for 915 owners.

Factory synchros are not like any other. They don't synch as well as other designs and if in good condition, won't maintain that condition for as long as one would like.

Long term cure? Learn how to properly double-clutch. With practice, it becomes second nature. Your gearbox will love it and you will become a better driver. And that's with or without that device strapped onto your 915 shifter.

Sherwood
Seine Systems

[jjeffries]

Duc, what got replaced in mine was the synchro bands/rings and dog teeth for 1st and 2nd, and the 1-2 slider.

I'll add that something like 12 years and 5k miles before I got the car (it had one owner from new to 2013), a shop had been into this 915 and replaced the 1st and 2nd synchro bands/rings only; thus I too was trying to wait for them to "make friends" with the other parts for those gears but such rapprochement never occurred. And when it baulked even double de-clutching wasn't 100% effective, although maybe some of that was me, or as mechanics say, "the nut behind the wheel".

I'm as thrifty as the next guy, yet I took my 915 to a shop that everyday works on some of the most valuable P-cars any of us will ever see. Didn't that mean the repair would be spendy? No, because AA knows what they're doing, they don't hose people and were happy to limit the scope of the repair to the problem at hand...and they know more than I ever will as to which of the existing parts could live another day. Could something else in there wear out next year? Sure, but I'm happy with the odds. John

[Duc Hunter]

Originally Posted by 911pcars

I must inject my regular suggestion (rant) for 915 owners.

Factory synchros are not like any other. They don't synch as well as other designs and if in good condition, won't maintain that condition for as long as one would like.

Long term cure? Learn how to properly double-clutch. With practice, it becomes second nature. Your gearbox will love it and you will become a better driver. And that's with or without that device strapped onto your 915 shifter.

Sherwood
Seine Systems

I am very familiar with 915 shifting. I have several friends with 915’s, I also have a G50 car too. I find properly 915’s need a “pause” moving from 1st to 2nd to let things synchronize. As long as you take the 1/2 shift with a slight pause in neutral, just being deliberate with it, they shift great. They are not a G50, or a any other transmission that you can just rip through the gears. My 915 though is not right at all. The synchro-brakes are just too stiff and often don’t let it drop into 1st or second. Good news for me is it is a fresh rebuild, and other than this issue, it should last a long time, giving me the opportunity to spend my money elsewhere.

Originally Posted by jjeffries

Duc, what got replaced in mine was the synchro bands/rings and dog teeth for 1st and 2nd, and the 1-2 slider.

I'll add that something like 12 years and 5k miles before I got the car (it had one owner from new to 2013), a shop had been into this 915 and replaced the 1st and 2nd synchro bands/rings only; thus I too was trying to wait for them to "make friends" with the other parts for those gears but such rapprochement never occurred. And when it baulked even double de-clutching wasn't 100% effective, although maybe some of that was me, or as mechanics say, "the nut behind the wheel".

I'm as thrifty as the next guy, yet I took my 915 to a shop that everyday works on some of the most valuable P-cars any of us will ever see. Didn't that mean the repair would be spendy? No, because AA knows what they're doing, they don't hose people and were happy to limit the scope of the repair to the problem at hand...and they know more than I ever will as to which of the existing parts could live another day. Could something else in there wear out next year? Sure, but I'm happy with the odds. John

Yeah your behavior sounds somewhat like mine. Sometimes mine wont drop in even when double clutched, esp at stoplights going into first. I will eventually get mine taken care of. Unfortunately I am in Florida, or I might give AA a call. RS Motorworks did the work on my tranny for a previous owner. Receipt says it was “completely rebuilt in house,” and they replaced all of the synchro rings (assume those are the synchro brakes), 1-3 hubs, 1-2 OP sleve, pinion bearing, & differential bearings. This work was done in 2012, and ironically was $1,400.