I replaced this seal once already, but obviously did something incorrect because I still had a leak to the outside. I have a '78 308, a new shift shaft seal kit from T. Rutlands, and will be attempting to do this again soon. Any tips for how to get it right? Or, gotchas to watch out for?
A light smear of DC111 seemed to help reduce the chance of nicking an o-ring. https://www.walmart.com/ip/Dow-Corning-111-O-Ring-Valve-Silicone-Lubricant-Sealant-FDA-NSF-Scuba-2oz-57g/457412385?wmlspartner=wlpa&selectedSellerId=17414&adid=22222222227140042582&wl0=&wl1=g&wl2=t&wl3=250468105876&wl4=pla-412965826705&wl5=9026542&wl6=&wl7=&wl8=&wl9=pla&wl10=120820736&wl11=online&wl12=457412385&wl13=&veh=sem&gclid=EAIaIQobChMI_vuP1am54gIVka_sCh2-7ggyEAQYDCABEgKDi_D_BwE
A timely question! I am currently in the process of changing mine too. Still disassembling; no tips yet.
I replaced mine earlier this year with the X seals. I also used fine grit paper on shaft end and oiled up the seals and the shaft with motor oil. I made sure the channels through which the shaft passes were absolutely clean. Since the seals were the X variety, the seals hold a little oil. I thought it was difficult to get the shaft to pass through the seals. I had to resort to holding the non sealing end of the shaft with vice grips and slightly rotate the shaft as I pushed it through the seals. The fit was very tight. Shifting was rather stiff for about 500 miles. The original 32 year old seal that separated motor oil from transmission fluid leaked allowing motor oil to get into the transmission.
Leaking motor oil into the transmission is the worst possible scenario as that can destroy the sychrnos, based on common wisdom here. I *think* my issue is with leaking to the outside at the position where the shaft exits the gearbox at the front, not inside the system.
One thing to check: (IIRC) they saved a few cents in manufacturing cost, by swagging a steel washer into a counterbore to form the groove for the oring (rather than machining a groove). Sometimes people wrongly think that this washer has to come out to replace the oring (so it gets mucked with). Confirm the washer is still tightly swaged in place to the aluminum.
I have now reinstalled my shifter shaft so now have a few “tips”: - Verell’s idea of inserting a (smooth) socket 1 mm narrower than the shaft is a good one. The shaft has a bit of a taper, but the socket makes it easier to insert the shaft since it pre-stretches the seal. - If your car is a US-spec with the aluminum shrouding on the exhaust headers, you might tap a small dent in the shrouding to allow the forward shift rod to move higher and out of the way to give more room to remove/insert the shifter shaft. - I neglected to clean the grease I was using off of the shaft before reattaching the shifter fork. I need to remove the fork again as it is slipping with grease underneath. - Does anyone know the torque spec for the bolt holding the shift fork?
Page M6 in the 308GT4 WSM has: Gearshift forks Thread = 8 x 1,25 Tightening Torque = 2,5 Kg-m (about 18 ft-lb) (but confirm the thread size is M8 x 1.25P)
Just did mine today. First attempt with the quad seal resulted in it breaking apart upon shaft insertion...
I think the first two broke on mine before the third was successful. Even using a drift that was machined to the same diameter as the shaft but with a slight taper on one end to spread the x-ring. If I did it again I would just use the factory o-rings.
Good afternoon Kevin, I have a 328(which I suppose is the same). Ran into that problem 2 times, First time I bought it from Superformance and failed not too long after installing. On the second try I bought the seals (it uses 2 seals, one between the crank case and gear box and another one where the shaft enters the crank case), from a hydraulic spare parts store... Has never failed again, and that was at least 4 years ago. Each seal was about 6 Euros. Second time I replaced both because apart from the "drip", crank case back pressure started blowing into the gear box and transmission oil started dripping out of the gear box breather. Hope this helps, John.
Kevin, based on my experience if one fails the other one is close to failing. Once you remove the shaft, replacing both seals is a piece of cake. Removing the shaft is the PITA. John.
The quad seals are very tight. I remember having to help it by grinding down the tip of the shift shaft so that it has a more pronounced taper.
I thing it's a straighforward but a bit time consuming job, but I also think, the X-rings are not worth the trouble while installation and creating a stiff shift feeling. Clean work with the stock O-rings does the trick. What can be tricky, is getting the old O-rings out of their seat. I used a dentist's probe and was careful not to damage the surrounding aluminium with its sharp tip. Performed the job 15 years ago while replacing the shifter rubber bushing. Still tight and dry after all these years. No motor oil inside the gearbox. Best from Germany Martin
Hello all, If you guys need "quality" seals(exactly the same size as original) send me the seal and I can buy as many as you want...over the counter. This is a common seal, used in many applications, don't know the actual price, but its not expensive. Hope this helps, John. BTW for those living outside Europe freight may be expensive...That's where it hurts
I refilled my engine and transaxle oils yesterday and took my car out for a spin. Today I removed the fill plug on the transaxle to confirm that no motor oil was passing into the gearbox and visually inspected all the other leak points (external shifter shaft seal, pan gaskets, dipstick union, oil temp sender, etc). Right now, I have no leaks whatsoever. First time since I've owned the car! A couple more thoughts regarding installation: The game changer regarding getting the shifter shaft back in after installing Unobtanium Supply's stiff quad-seal is pre-stretching the seal with something about 1 mm smaller diameter than the shifter shaft. Verell recommends this method. I used an old allen socket which was perfect (see photo). It had no size or manufacturer stamps on it so was perfectly smooth all the way around. It also had a taper in the middle which made insertion through the quad-seal easy. The shifter shaft has a small chamfer on the end which stretches the quad-seal that last 1 mm. I pushed the allen socket into the quad-seal and then pushed the allen socket all the way through with the shifter shaft. I won't overstate the ease; it is still a battle because there is no room to work and the seals are tight, but it was doable and I did not damage the quad seals. My other comments relates to the disparaging words about the shifting stiffness with the quad-seals. To me it was a noticeable but minor difference. In someway I like the new feel as it feels more precise. I will soon not even think about the difference. Image Unavailable, Please Login
