Hard shifting

[EugeneYu]

I have a 87 924 with 150k miles on it.
It is hard to put on reverse or first gear when I'm trying to move the car from parking. It happens most time but not every time. After I put the shift to other gears, it will be easily to put into either reverse or the first gear. There is no problem when I drive. BTW, I don't feel anything wrong with my clutch.
What's wrong with it? Please give me some hint and ideas, my friends.

Eugene

[no1biscuit]

I have an 86 951 and I have the same exact problem. Im sure the guys on this message board can help us.
Thom

[eimkeith]

Try swapping the tranny fluid with a synthetic (mobil 1 or Redline). This often helps hard shifting to reverse and 1-2 in the cold.

[pst]

If the oil change doesn't help, you most likely have worn syncronizers. What you describe is typical of worn dog teeth and sliding hubs. These are the teeth that are on the side of each gear and sliding hub.

[e_nough]

my syncros are shot but dog teeth are fine, and i called a local mechanic that has been around for a while about my tranny, Ryland's in atlanta.

he says if you only have problems in 1st and R then you have clutch problems because this is an indication that the clutch is not disengaging all the way and you are forcing the tranny into gear while its still moving. which means problems with the hydraulics (master and slave cylinders) or problems with the throw out bearing and related parts but not necessarily the actual clutch disc.

to check your dog teeth gears find a steep hill to drive down, put it in 2nd and let off the gas. as you drive the engine is holding your speed back and the tranny should stay in gear, if it pops out own its own you have worn out dog teeth gears, do the same test in 3rd gear.

if the syncros are bad you will hear grinding as you shift, especially into 3rd, and louder grinding when it is still cold in the morning. you can drive the car as if it does not have syncros (like an old tranny that didnt have any in the first place) until you can get this fixed. but dont wait too long.

[e_nough]

here is another test

put the car on blocks and find the rubber plug on the clutch housing. remove the plug and you will see the end of the lever arm that disengages the clutch. have someone sit in the car and push the clutch all the way in. this lever arm should move 18mm. measure this. if it is less than around 15mm then you have problems with something in the clutch.

[e_nough]

no1buscuit,

how many miles do you have? what year? have you already replaced the clutch?

[pst]

Jumping out of gear id only one problen caused by worn out dog teeth. Difficulty engaging gears is also a sign of worn teeth. I aggree that the disk may be worn. If the disc is worn, it can tend to stick to the flywheel or pressure plate surface causing strain on the syncronizers. When this happens, reverse will grind when trying to engage it. The dog teeth are pointed as are the teeth on the operating sleeves. This is done to guide the teeth together. When the syncro. rings wear out, the teeth gring during engagement and eventually wear the points off of the teeth. When the points are worn away the opoerating sleeve cannot guide easilly onto the dog teeth. This is what makes it difficult to engage a gear.

[e_nough]

pst, i agree.

[AMCPorsche924Powerhaus!]

well this isn't going to fix your problem, but IN THE FUTURE any time you are going to go into "first", you should put it in "second".
So like when you are stopping at a light, always put it in "second" before you put it in first again.
Even if you put the clutch in and use purely the brakes to stop, you have to put it in "second" with the clutch in and then in "first" because it helps line everything up in the tranny so that stuff don't get worn.
Now you find your self HAVING to put it in second before you put it in first, that is because that is what it needs to line up, and for preventing purposes, you should do this all the time!
Only problem is I don't know what is best for the type of tranny in the 931 or most 924 early ones, the racer pattern or snailshell as they call it, since its a different pattern and all.

[This message has been edited by AMCPorsche924Powerhaus! (edited 02-08-2001).]

[e_nough]

hmmm, ive never heard of shifting to 2nd and then 1st, but that makes sense because you are slowing all of the rotating parts down before you shift to 1st.

does anyone else do this?

is this actually recommended by porsche?

[EugeneYu]

I did have transmission fliud changed today, but not syntheic. It helps alot. And the overall shifting get much smoother.
I don't know why.
no1biscuit, Thom, have you solved your problem? How?
Eugene

[hoff944]

I never shift into first gear while rolling unless I'm going really slow.

[EugeneYu]

I was really mean shift around when car was in parking. It got easier to shift into 1st when start to drive from stop.
But my problem is kind of solved after fluid chang.
Eugene

[mjade924]

Originally posted by e_nough:
hmmm, ive never heard of shifting to 2nd and then 1st, but that makes sense because you are slowing all of the rotating parts down before you shift to 1st.

does anyone else do this?

is this actually recommended by porsche?

thats the way my father shifts .. and its the way he taught me to shift ...

[no1biscuit]

e_nough
I have an 86 with 157K. I don't know what mechanical work that has been done to it. I have had it a year and I think previous owners have not taken care of her. Now I am paying for it.
Thanks
Thom