z driver 88t

I need to check my trans oil level due to a very small leak (approx one drip a week, and want to be safe).

I did search but looks like a little conflicting info on the hex bolt size as to whether or not it is a 17mm or 18mm. Can anyone confirm which it is before I crawl under there with a set of dial calipers? I'll need to order the correct tool or make one with a bolt and want to buy the correct size and avoid multiple purchases.

1984 US model, 5 spd, LSD. Thanks.

Landseer

17

Manfred

Anyone know whether it's the same size in a '91GT. I think I saw a thread at one point that indicated they were smaller in the later models but I can't find that thread again.

Rob Edwards

Should be 10mm hex on a '91 GT.

Manfred

Thanks Rob.

RCinXS

I have a 928 Motorsports transaxle differential socket / hex key for sale. It worked on my 84 Automatic. If you are interested, I'll out it up on Ebay for you.

Landseer

All you need is a heavy hex socket. Metric

You can buy a very heavy duty 1/2 drive blackhawk at NAPA or something adequate just about anywhere.

Rob Edwards

Or you can double-nut a short-ish M10 bolt (steal one of the bolts that holds the front LCA bracket to the frame rails) and stick its 17mm head into the plug, then use a 17mm wrench on the inner nut to turn it out.

Kroil the hell out of the plug first, you don't want to strip it. And loosen the upper fill plug first.

Mike Frye

And when you put it back on, use a torque wrench. The tendency with these seems to be to put some ungodly amount of torque on there because of the size of the wrench it uses. I think that's why they went to 10mm in the later years. It just has to be tight enough to keep from backing out, it's not holding the axles in or anything.

22nm = 16.22 ft/lbs. That's almost what you get with one finger on a 1/2" drive, which is usually the only thing that has a 17mm allen head socket.

Manfred

Hey RC,
I think your key's gonna be a different size than what I need. Thanks for the offer though.
Dan

Manfred

Yeah, I guess people worry about the bolts loosening unknowingly as you drive down the road but you're right, it's not like they're holding anything together.

Yup, gleaned that from other threads; could easily see making that mistake the first time...

Thanks for everyone's help. I'll make sure I get a 10mm hex head and a torque wrench in my box before getting my car on the lift.