Thinking about trying to rebuild a 5 speed for the first time

[Zedyone_kenobi]

Greetings Z buddies.... Been a while since I posted as I have been working my website and reignited an old passion of mine with collecting mechanical watches.  Guess I am getting old.. 

 

But seriously... I have finally acquired a 5 speed from a 77 280Z and have been calling around to get it rebuilt.  It seems to work fine on the garage floor.. Spins freely and feels smooth... but before I put it into my car, I want to go through it completely.

Having said that I am getting prices to rebuild an old 5 speed in the 900-1300 dollar range. That seems excessive since I had my 4 speed redone for 650.  

 

well the mechanic in me sort of wants to give this a try.  What I need from my fellow brethren is any shop manuals specifically for the transmission.... is there a handy dandy resource to redoing these. I know some of you have done this.  before I crack the case, anybody want to throw a reference or two out.

[cbuczesk]

We're going to be rebuilding a few 1972-ish 4-speeds for our race cars next month. Our friend Steve is the brains and the rest of us do the grunt work. You're welcome to bring your 5-speed and join us. We use the FSM for reference during the rebuild.

Chuck

 

[siteunseen]

I paid a transmission guy to pull mine apart and inspect.  He told me to buy two seals, put it back together all for $100.  Said the internals looked great.  Been driving it for 6 years without any problems.  Early '77 5 speed.

[Zedyone_kenobi]

Well I called up Awesome Z, good place in Houston. He rebuilt my 4 speed which has been working properly now for over 5 years for 650 bucks. When I asked him to look at this 5 speed, he said 1250.  Just now way it is that much harder.

[cbuczesk]

The transmissions are pretty tough. It might not need anything. Maybe a syncro or two since you're in there and of course the front gasket. If you take it apart you should replace the roll pins and maybe add a second pin while you're in there. If the transmission is used hard the roll pins will shear. That's why we double pin them on the race cars.

It costs more to rebuild the 5-speed because the 5th gear syncro is made of gold!

Chuck

 

[Zed Head]

For the prices you're looking at it might be most effective to just put the two new seals in, install it, use Redline MT90, and see how it works.  I think that you can replace the countershaft bearing pretty easily if you wanted to do one bearing also.  It's the noisy one.

Once it's in if you'll get a better idea of how much it needs.  Odds are, if a synchro is bad, it will be just the 3rd gear synchro.  The others will probably be fine, and probably better quality, worn, than new aftermarket synchros.

Edit - I'm a slow typer...

Edited January 9, 2018 by Zed Head

[Jarvo2]

I’m hoping to rebuild mine too!


Sent from my iPhone using Classic Zcar Club mobile

[Zedyone_kenobi]

Bingo! Found a local manual transmission shop that said he will be happy to take it down and have a look. He said it probably does not need a thing but some seals, but I have no way of knowing. He said he will take it down and check it out to let me know its condition.  Said it should only take a day or two.  I like not fixing what is not broken.  I will update when I get a chance.  I will mention to pay close attention to the roll pins and 3rd gear syncros as well.

 

[siteunseen]

I bought the Timken seals, one big one and a smaller one from a local parts store.  Less than $10. 

[cbuczesk]

Have him replace the roll pins. They're super cheap.

Chuck

 

[Zedyone_kenobi]

GREAT NEWS..

 

UPDATE:  I have my newly rebuilt 5 speed sitting on my garage floor. Next steps are as follows:

 

1) Clean the thing up and make it look factory fresh

2) Give some hard thought to replacing the clutch/pressure plate/throwout bearing (only have 3000 miles on my last new clutch installed 5 years ago)

3) Fill with MT90 and have fun.  

NOte: I plan to use the clutch fork, throwout bearing, Clutch collar, clutch and pressure plate from a 240Z 4 speed.  I think it should be the same. 

[Zedyone_kenobi]

UPDATE: I have been so busy with baseball I have not had a chance to post in a long while, but the transmission is cleaned up and ready to install. Ordered an new clutch and pressure plate. I may or may not change those though as I only have 3000 miles on my stock clutch. I will change out the throw out bearing though for sure.