dnwong

I test drove a friend's 951 last week and found that his transmission shifted so much smother than mine. Both cars have the Schnell short shifter kit installed (I installed them).

My car is original and 95K miles while the other has a rebuilt trans (car has 160k, not sure about the trans).

My first and 2nd gear are really tough to get into but his shifted smoothly in all gears. They are both LSD (I think), but his has the external oil cooler.

Does anyone know what needs to be done on mine?

Techno Duck

Other than changing the gear oil there is not much that can be done short of rebuilding the transmission. That will run you in the area of $1500 +.

alordofchaos

... so it's a good idea to start out with flushing out the old gear oil, adding some fresh synthetic (Swepco, Redline, royal purple, etc.), and crossing your fingers... hope it's good news.

I have to add that before i did this, mine was hard to shift into 2nd, shift much more smoothly after changing over to Redline.

However, you must confirm whether you have LSD before you get your gear oil, because there are two formulations depending on whether you have it or not.

BTW - I'm of Asian descent, if IIRC, Jon is also... and guessing by dnwong's name, that makes 3 of us in a row in this thread?

harrisonrick

Sounds like your syncros are showing their age...change oil as stated, and ease it into gear from 1st to 2nd. NO GRAG RACING DUDE!

I also hear that double clutching will help for really worn syncros.

If you decide to rebuild, the tranny isn't too hard to re and re yourself if you are handy...would save you big $. The syncros are not that expensive either...I think 944online sells them for @ $40 each gear.

Call Ian and he could price out the needed items for a rebuild or sell you a fully refurbished one.

xsboost90

so is your clutch adjusted correctly- if its not going far enough in you may not fully be disengaging the clutch.

Techno Duck

Yup i am 3rd generation ABC. Im about as much of a twinkie as they get.

I would advise against cracking the tranny open yourself to change the synchro's. Ive read the shop manual on it and looked at the diagrams. It makes my head want to explode. Did i mention i am a mechanical engineer?

Even then it requires some specialized equipment, mainly a hydraulic press...which not everyone has in there garage (though i do know someone that does).

I have driven a friends 951 with a rebuilt transmission and was utterly amazed at how smooth it shifted. It was kind of spoiled by a warn shift rod and it took some getting used to the stock throw length... but it was a great to feel the way a 944 series car is supposed to shift.

One day ill get a spare transmission and have it rebuilt, throwing in a aftermarket LSD while im at it. I dont expect that bill to be less than $2500 though.

Double clutching helps, especially for the first mile or so of driving. My 1st to 2nd was very hard to engage also when i bought the car. I put in Redline fluid (and also have the 944Online short shifter which is basically the same as the Schnell) and it helped, but still didnt go away completely. I usually double clutch into 2nd for the first mile or so until everything warms up. It still takes a light touch, but never grinds anymore.

dnwong

Yep, change the gear oil to Mobile 1 recently. I think its a little better but still notchy.

Yes, I am asian.

dnwong

The clutch on my car does engage much lower then my friends. But I just had the clutch job done a few months ago at shop. I could try to raise the pedal a little.

But 3rd 4th and 5th are fine...

AlpharettaRK

Also you can try bleeding your clutch slave cyliner. Any air would keep the clutch from fully disengaging and I think you would notice this more in 1st and 2nd than in other gears. A symptom would be that the pedal would travel more as it compressed the air.

Good Luck
Cheers
Randy

ubercooper

Its the syncros, I have the same problem with my 89 with no SSK. Until I can afford a new trans I am going to just shift slowly from 1st-> 2nd.
-Seb

alordofchaos

I'd be a little worried - you may want to confirm you have a limited slip and double check what you put in... when I was looking at Swepco and Redline fluids, they had different formulations for LSD and open diffs. You don't want to make an iffy situation worse by having the wrong oil in there...

dnwong

I definitely have an LSD, I was not sure about the other car. Is Mobile 1 compatible with it. Where can I found out what the approved oils to use?

alordofchaos

Sorry! False alarm (hopefully).

When I looked at Swepco, Redline, etc., they had different forumulations. Looking at the Mobil site, it looks like Mobil's gear oil is for both:
"Mobil 1® Synthetic Gear Lube LS 75W-90 is a supreme performance, synthetic, multi-purpose, SAE 75W-90 automotive gear lubricant designed to meet the highest level of performance requirements of modern passenger vehicles in all types of operating conditions, including limited slip applications, as well as delivering outstanding power transfer performance."