5th gear problem?

[mjr45]

Just got my car back from the exhaust shop and having not driven it more than 2 blocks and never out of 2nd, found a new issue. When trying to shift into 5th all kinds of grinding and won't go in when in motion. It will go into 5th when sitting but as soon as the clutch is released pops out. All other gears shift fine, including reverse but are a little stiff. The local tranny shop wants $1000 to rebuild it! Tranny is from a 79 ZX. Thanks for any input.

[Gary in NJ]

5th gear? Show off.

$1,000 seems to be the going rate. Check out the shop and make sure that they really rebuild transmissions.

[Carl Beck]

Do they want $1000.00 to rebuild it? - - Or do they want $1000.00 to pull it out, rebuild it and re-install it? Most Z Shops will rebuild your 5 spd. for around $550.00 or less if you pull it out and take it to them.

Have you tried - double clutching - before going into 5th? ie. Push the clutch in and put the lever out of 4th - let the clutch out - then push the clutch in and slip it into 5th? If that works - you may only need new synchro's - or you may just have a loose nut in there.

Can't remember exactly when - but the nut on the Main Shaft used to come lose on the earlier transmissions - they fixed that by having a reverse thread on later models. Someone else may have a better memory as to when that took place...

Nonetheless - just because you can't get it into 5th - doesn't mean that it needs a complete overhaul.

I'd try to find a good "Z" mechanic in the area....

FWIW,

Carl B.

[mjr45]

Yup tried the double clutch trick, no joy, sitting still I can put it into 5th and as soon a I let out the clutch it jumps out, if I try to hold it in and let out the clutch it grinds like hell. Carl I agree it probably doesn't need a complete rebuild, and finding mechanic's around here who know anything about Z's is close to impossible, even the one in Colorado Springs who works on "Nothing but Japanese" cars told me he would be lost working on the Z. I have found a couple of tranny shops that say "they can fix it" but I don't know. The other thing is that for less than the $ to rebuild I can find another used one.

Edited April 22, 2012 by mjr45
new

[olzed]

Find a used one.

[Zed Head]

I've read the 5th gear shift fork is weak on the 5 speeds since it was designed in as an add-on to the 4 speed. You might have a broken fork keeping 5th from engaging completely. It's shared with reverse so reverse might be affected also.

That would actually be a pretty easy fix, since 5th gear is in the tail shaft housing. If you have the time to keep the car down, maybe pull the transmission and take the housing off to see.

I attached a picture from the 1978 FSM. The ball bearings shown are in the adapter plate which is between the main gear case and the tail shaft housing. You can see that the 5th (OD) and reverse shift fork is essentially half of a full fork.

Edited April 22, 2012 by Zed Head

[mjr45]

Thanx Zed, I plan on pulling the tranny this week and since this is not my daily driver and has been down for about a year a little longer won't matter. Another question; I've read a couple of posts regarding the shift lever, the one I'm using is from a 75 4 speed and doesn't look like the one in the diagram, does that matter?

[Zed Head]

It shouldn't matter. I am using my 76 4 speed lever on my 1980 5 speed. The 71B transmission cases, which yours and my (mine?) 4 speeds came with, and which was used in both 4 and 5 speeds up to 1983, all have the shifter attachment in the same location.

[mjr45]

I didn't think it did since there are no clearance issues in the opening in the tunnel, but just wanted to be sure. Thanks.

[tlorber]

If you have the tranny open you should replace the baulk (synchro) rings AND bearings. With the labor involved, the parts cost in rather inconsequential.

[mjr45]

Tranny is not open, I a little fearful of taking that on besides I'm still stuck on the*#**ing EFI.