Tools & supplies required for G50 trans fluid change?

[r-mm]

I have 4 qts of gear oil per owner's manual specifications, an oil pump and a 24mm socket to release the drain plug. I can't find a description of the fill plug but from the parts manual it looks like its a big female hex (which sounds dangerous). Also wondering if the sealing rings around the grain and fill plug must be replaced or if I can get away with the old ones.

Thanks

[964TargaC2]

First off make sure you can take the fill plug out before you do the drain plug!

IIRC the plug is 10mm hex, dont think factory put a washer on the fill plug but it is a good idea to do so, they are cheap. I have heard of some guys smoothing them down with a file and reusing them..I dont do that..

[porschenut]

I just did that job on my '88 last weekend. Both the drain plug and fill plug are 10mm female hex, so you need an allen wrench or allen socket (unless your plugs are different for some reason).

Always use new ring washers on every plug (both engine oil and gear oil).

[r-mm]

Originally Posted by porschenut

I just did that job on my '88 last weekend. Both the drain plug and fill plug are 10mm female hex, so you need an allen wrench or allen socket (unless your plugs are different for some reason).

Always use new ring washers on every plug (both engine oil and gear oil).

Did you get the ring washers from Pelican or from an auto parts?

[Justin@Athens]

If you have a motive or other brand brake bleeder, or a garden variety bug sprayer--it makes it alot easier to change the fluid--I outfitted my bleeder with an inline on/off valve too, so that I could better control topping off.

[kidrock]

I just did this job a couple of weeks ago. You may need a small breaker bar to get those fill plugs loose. One of them was super tight, so I used a small jack under the breaker bar handle and gently jacked it until it popped loose.

[A horse with no name]

Originally Posted by r-mm

I have 4 qts of gear oil per owner's manual specifications, an oil pump and a 24mm socket to release the drain plug. I can't find a description of the fill plug but from the parts manual it looks like its a big female hex (which sounds dangerous). Also wondering if the sealing rings around the grain and fill plug must be replaced or if I can get away with the old ones.

Thanks

Hi...What will work well if you don't want to purchase a 10mm hex, is to weld a good grade 10mm hex nut onto a larger bolt of your choosing. _ Keep the overall length short.

[A horse with no name]

By the way...You do not need a washer as they are tapered.

[KTL]

The 915 plugs are tapered metric pipe thread which is self sealing since the threads on plug vs. trans case create interference due to the taper. Which I think is stupid because they invite seizure. That's why they don't use seal rings. Shouldn't use tapered threads on something that's intended to be occasionally taken apart, unlike pipe systems. and do not use seal rings.

The G50 uses straight metric threads and the plugs do have a shoulder and do use seal rings. Incidentally, the seal rings are the EXACT same size as the rings for the oil drain plugs on the engine case and oil tank. Seal rings can be reused if you don't have any new ones. Think about it, they're a mild squish under a fair amount of torque, and not sealing under pressure. So it's not really hard to get a good seal when reusing them.

Just don't overtighten the drain plugs. Even with proper "straight" threads, the G50 plugs also tend to get stuck, even when tightened to the proper torque spec. 22 ft lbs (30 Nm) is the number.

[r-mm]

Originally Posted by KTL

Just don't overtighten the drain plugs. Even with proper "straight" threads, the G50 plugs also tend to get stuck, even when tightened to the proper torque spec. 22 ft lbs (30 Nm) is the number.

Thanks for the tips. Is there clearance to get an electric impact wrench (with 10mm hex attachment) to the fill plug ? Based on Kidrock's description of a jack under a ratchet it sounds like the breaking torque would be more safely (in terms of rounding the fastener and rocking the car) applied by impact.

[kidrock]

as far as clearance goes, yes for the drain plug. The fill plug? Eh, not so much. I don't have a lot of fancy tools (see "lift"). I just jack it up, put it safely on a stand on one side, and keep a jack or tire under the car while I yank on the breaker bar. Once I've removed the plugs, I insert the pump hose into the fill hole, then lower the car. Proceed to fill until the gear oil starts backing out the fill hole...close to 1 gallon, just a bit less.

[KTL]

Agreed drain plug is no problem. It's the fill plug that's the pesky sucker. Not much clearance there due to the clutch hyd. rubber hose and the throttle linkage bellcrank if I recall by memory. Your typical 10mm hex key with a length of pipe slipped over it, or a breaker bar with a length of pipe on it should give you the leverage you need.

Just resist the urge to tighten it too much. Snug is plenty tight. When you torque the drain plug (because you have so much clearance to allow use of a torque wrench), you're going to think "no way that's tight enough." It is. Because if you tighten it more, it's a real SOB to get loose later on. Mostly likely because the gear oil lubes it so well that you're technically over-tightening it

[kidrock]

probably going to get flamed for this, but I put a very small amount of anti-seize lubricant on the plug threads upon re-install. YMMV

[KTL]

Originally Posted by kidrock

probably going to get flamed for this, but I put a very small amount of anti-seize lubricant on the plug threads upon re-install. YMMV

So do I....... I think it's kinda futile because the plugs are still tough to loosen. I change my gear oil pretty often since I race the '79 and I used to take my '87 to track days too.

[porschenut]

Originally Posted by r-mm

Did you get the ring washers from Pelican or from an auto parts?

I get mine from Pelican. Every so often I order a dozen so that I always have a plentiful supply. They're only a few pennies each.

[A horse with no name]

Originally Posted by A horse with no name

By the way...You do not need a washer as they are tapered.

Sorry fellows ....I never knew that '87's had a normal plug with a washer -Do now