Hotrodbob

Anyone know if GM used synthetic gear lube in the manual trans?

If not, is anyone using synthetic?

Hotrodbob

No body changes trans gear oil?

oneton

There is a post with GM gear oil spec. for your trans on here somewhere

Hotrodbob

Thanks.. I'll do a search.

Hib Halverson

I'm not sure if the GM factory-fill lube in a five speed is synthetic or not. My guess is that it's not.

I use a synthetic in my five-speed.

Currently, as part of a test program on which I'm assisting Red Line Oil, I have their Superlight Shockproof gear lubricant in the trans. It's been in there for 30,000 miles and 2 1/2 years. The lubricant has worked very well. Shift effort actually went down slightly under all driving conditions except for during early warm-up. When the trans is cold, the shift effort is about the same as it was when I was using the stock lube. Once I drive a mile or so, shift effort decreases. This is typical of the Shockproof lubricant family.

That said, Superlight Shockproof is marketed as a racing lubricant and, when used in a street-driven transaxle, is still under testing. If you are interested in going to a synthetic for a street application, I'd suggest Red Line's "regular" GL4-rated, low-viscosity, gear lubricant, "MTL".

I used MTL for over a decade in the MG-292 five-speed I had in an 1988 Chevy Beretta which was my daily driver from 88-01 and 140,000 miles. It worked very well. the MG-292 was the forerunner of the Getrag five-speed in the HHR. Typically, a switch to MTL, given a transmission in good condition and a clutch that's working properly, will result in improved durability and slightly lower shift effort.

As for the factory fill lube, it's GM PN 88861800.

Hotrodbob

Thanks Hib, I have used synthetics in all my older cars manual trans for years. Usually Amsoil, but was not sure about the HHR. We did have it as an optional fluid on the medium duty truck line (Allison only), but that was an automatic. I couldn't get a answer from my old contacts.

I like the redline products as well. I'll look into that. I have 35k on the HHR now and cold (less the 70deg F) I can out shift the syncros. In the past Synthetic in my older cars would take care of that.

Thanks again and Happy New Year.

Hib Halverson

If you are experiencing gear clash on quick shifts when the trans is cold, I would definitely change the lube and go to a synthetic.

I'd also bleed the clutch.

If you still have the problem then you may have trouble with your trans, although with only 35,000 miles on the clock, I'd think that unlikely.