HELP! '87 trans. goes "CHUNK!" shifting into 3rd

[e_nough]

Yo!

Just got a sweet 1987 944 about 2weeks ago.

When shifting into any gear (into 3rd especially) the transmission makes a low dull "CHUNK" noise. You can feel/hear it behind and below the rear seats (duh this is where the trans. is).

The amount of noise and level of "CHUNK" depends on how fast/slow you move the shift lever into the new gear. If you shift fast it is sometimes louder, or if you shift really really slowly its really loud and sharp, and if you go normal speed its not so bad.

Also, the higher you rev the engine before shifting, the quiter and it is. e.g. if you rev. to 4000 - 4500 its much better than at 3000.

So what's the deal? I think the syncros are worn out (car has 111K miles). I had it inspected before purchase, and the guy said that if you drive down a steep hill in 3rd gear and the shifter does not pop out of gear, then the transmission should be ok.

any thouughts, what is that "CHUNK"??

do i need a new transmission, and if so should i go for rebuilt or new?

Thanks, Mike

[Porsche 951 Fanatic]

i would just rebuild it if i were you.....

------------------
PORSCHE-THE BEST!!!!

[e_nough]

Fanatic,

Thanks for the feedback. have you ever rebuilt one of these?

do i need special tools?

whats this about the shims between the ring and the case?

i have never rebuilt one of these, my level of experience does not exceed changing the brake pads, do you think i can figure this one out?

do i need the factory manuals to get specs for parts?

[Obin Robinson]

rebuilding a Porsche tranny is like working on a BIG swiss watch.

if you have all the tools, and the patience, you can do it.

if you are missing ONE tool, then you will end up with a big mess, and a big hole in your bank account.

buy a rebuilt one. but if you have the tools, you CAN do it yourself.

the list of tools you need is in the Porsche factory manual for the 951.

GOOD LUCK! (you will need it)
obin

[e_nough]

ok, i think not taking on the risk of a screw up is worth the extra $500-700 for the rebuilt.

does rebuilt necessarily mean that certain parts Will for sure be replaced, such as syncros, and dog teeth, or do they inspect and replace only the worn out parts.

thanks

[ckrough]

A friend of mine races/repairs 944's. When I bought my 90 944 S2 he told me to listen for a thunk in 3rd gear, he said that the factory clutch and OEM replacements have a rubber center in the clutch disk that breaks under hard driving and causes a thunk if you release the clutch quickly in 3rd. He said it just needs a new clutch.

[Dave951]

If it the rubber center clutch problem, you will hear it anytime you switch from accel. to deccel. or vice-versa by just using the throttle, regardless of what gear you are in(lower gears will be louder than higher ones, but ALL will make a noise). If your car doesn't do this, the rubber breaking is not the problem.

Dave

[Dave951]

By the way, I don't think that the S2 has a rubber disk. I believe it is spring centered. I may be wrong, but I am fairly certain.

Dave

[T86951]

When the rubber center of the 944 clutch goes bad it does make a slight clunk when you let out the clutch after gear shifts but in all gears. I have an 86na that I drive every day. My rubber section went out and it just had slack in the driveline when on and off the gas or letting out the clutch. The best way to tell is to put the car in gear motor off and rock it. If it acts like the ring and pinion have a lot of slack then it is more than likely the clutch center section. There are 3 metal fingers in there that catch things until you replace the clutch.
I am just about sure that the rubber center section was not used after about 86 or 87. I know the turbos don't have them cause I have an 86 turbo and I know the latter S2's don't. I don't think 88's or 89's do either. not sure about 87's.