Hi,

A 1984 Trans Am with TH700R4.
The little plastic shaft of the speedometer adapter is worn out
where is the seal on it. Can I buy such a shaft as new or used in a
very good condition? O know I can tighten the seal a little bit but
I think this would be not the best solution.

I mean the part with number 12 on this image:





As I remember it was a grey plastic shaft which rotates and the
speedometer cable is connected to it.

Which company sells it? The dealer here does not have it.

Thank you,

Laszlo

 

The diagram you're showing isn't for an 84 transmission. The shaft is part of the speedometer gear. They should still be available from GM, or a transmission vendor on the net.

 

Not sure if an 84 trans is different from later years, but I'd go here to get the speedometer housing if your local dealer can't help. And these are aluminum ones not plastic. 700R4 applications are at the top of the listings. I've dealt with this company to supply the parts I use to convert T56's to a cable drive speedometer and they have come through for me every single time. I highly recommend them.

http://www.transmissioncenter.net/sp...__va.htm#700r4

 

Hi,

The diagram is from the repair maual of the TH700R4 which
I used when I bought the other parts like seals. It always worked.
I was at a GM dealer and he looked at the same picture in the
computer and that part, the shaft did not have any product
number which means it can not be ordered.

Can you tell me the GM product ID number of that part of a TH700R4?
Then I would go with that number to the dealer.

Thank you,

Laszlo

 

The diagram shows a VSS for an electronic speedometer. Your cable driven speedo uses different parts.

 

Thank you. The transmission center has the plastic shaft which it together with the driven gear.

I need your advice:

- if I remove the retainer, can I just pull out the plastic speedometer housing and then the shaft with the gear?

- I need to know how many teeth my driven gear has. Can I find this out without removing the shaft with the gear? 1984 Trans Am, TH700R4 overdrive, original tires I think 215/60R15.

Thank you,

Laszlo

 

Yeah, just undo the retainer and you can pop the whole assembly out in a couple of seconds. Then just count how many teeth are on your gear. I highly recommend using the company Alloy suggested. They ship worldwide and carry every speedo gear you'll ever need for a 700r4. They're very affordable too.

 

Thank you.

Does it make sense the replace the plastic housing with a new one? Can it be worn and then it does not hold the shaft straight and then the shaft moves to the side and the seal will be worn sooner?

Laszlo

 

There's no seal between the driven gear shaft and the housing. ATF is allowed through there to lubricate it. The plastic housings don't wear, but they get brittle and break with age. Replacements are aluminum.

 

Hi,

How deep should I put the seal into the housing?
Should I just push it in until it is in the housing or should
I push it in as deep as possible? Where should the seal touch
the shaft? Place A or B on the 3rd picture?

I think if is it not total deep in it then it touches the
shaft at the wrong place where the shaft is too thin.
Am I right? I think I should it push it totally deep, right?
Maybe that was the reason why the old seal got a hole
because it touched the shaft at the wring place.

Thank you,

Laszlo

 

Nobody knows how deep to put that seal?

And the seal is not hard, I think it can come out easily.
Does anybody know what holds the seal in the hole?

It would be very urgent to know...

Thank you very much,

Laszlo

 

location B would be fine.

 

OK, thank you. But the seal is soft. Something should hold it in that
position, right? In that deep position in the hole of the black housing.
But what?

Thank you,

Laszlo

 

No additional parts hold the driven speedo gear in the sleeve (12.)

The drive direction of the gear against the teeth of the drive gear push it towards the sleeve, so it stays put.

You place the driven gear and sleeve into the side of the tailhousing and it will stay in place.