I have a manual 02 with 34,000 on it and am going to change out the transmission fluid shortly (has never been changed). My question is should I also change the diff. fluid at the same time since I will already have the car up on the rack? And if so, can I use the same pumping device to change out the diff fluid? Should the Dexron IV fluid be flushed from the pump first, so as to make sure there is none still in there? And I suppose I would get the red line gear diff fluid I have been reading about that already has the additive in it? Thanks in advance for any suggestions.

 

I use the same pump for both the tranny and the differential. You need to make sure that at least most of the DT4 is out of the pump before you go to the 75-90 but it doesn't have to be surgically clean.

 

Do the ATF first, then pump gear oil through the pump until it's clean and then fill the diff. If you are using big dollar oil, get some cheap stuff to flush the pump. I would make certain you are putting only the appropriate fluid in the diff or trans and flushing the pump thoroughly is not overkill.

 

if you are that paranoid, then just get two pumps. they are cheap.

 

- thats what I did -probably more cause to lazy to flush

I also used Amsoil for both and no issues.....

Member Subdriver can hook you up if interested....

 

I wouldn't worry about it that much. There are going to be a couple ounces of the old fluid in the rear end after draining it any way. The small amount in the pump will not make tha much difference.

 

I made a suggestion to the OP...I have an electric gear oil pump and a dedicated ATF manual pump. I would never consider using one pump for both, but if someone wanted to...flushing the fluid would be the way to do it properly.

As for the other posters suggesting it's okay to have a little of either in the other....not good advice. While it might not cause a failure, there are distinct differences between the viscosity and additive packages and in some cases (fiber blocker rings come to mind) gear oil will damage the trans....why go through bother of changing fluids if you are going to compromise the integrity of one or both?

 

Subdriver can hook me up with a good deal on the amsoil products that I need? How do I find his email?

 

Brad will take care of you...left side of webpage lists contact info.

http://www.c66racing-synthetics.com/

 

Thank you much

 

Bingo!!




That's what I did, as the pumps are around $5-$6 each, and will last forever....

 

Thanks all for the mentions.

Dobeman2000 - answered your PM.

FYI, for those skimming the thread, these are the fluids AMSOIL recommends for the C5/C5 Z06 and what I've been using in my 02 Z06 at the track for years:
AMSOIL Torque-Drive Synthetic Transmission Fluid (Product Code ATD1G)
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
Note: the Severe Gear 75w90 has friction modifier in it and adding extra is not needed to prevent diff chatter in the C5/C5 Z06.

Addressing a few other comments above. The original post by Dobeman2000 mentioned Dexron IV. The current GM automatic transmission fluid is Dexron VI. The viscosity on this fluid is much less than that of the original spec fluid in our owners manual, which was Dexron III. The AMSOIL fluid linked above meets the Dexron III spec.

For those that prefer GM, GM discontinued their branded Dexron III, then rereleased essentially the same fluid as a new GM part 88861800.

Here is a quote from a TSB of 2007 on the topic:
"Manual Transmission fluid part number 88861800 U.S. (88861801 Canada) is currently available through GMSPO. Current and past model vehicles listed above with either a manual transmission or transfer case that REQUIRE Dexron III should use the above listed manual transmission fluid. This fluid is a direct replacement for Dexron III in manual transmissions and transfer cases. DO NOT use Dexron VI in place of the manual transmission fluid in any manual transmissions or transfer cases as a failure may result."

Final point, many drain the hose on the pump and reuse the same pump. The small amount of mixing will be trivial to the overall volume of fluid pumped. That said, I use two pumps.

 

"Sub", just a quick question,if you don't mind...


As you know, there have been hundreds of discussions of tranny and diff lubricants, due to paper blocker rings, etc. Every lube maker has their own additives, as well as their own claims of superiority. My question, is there any risk of changing brands of lubes?

I have a 2001 C-5 6 speed, and the year after I got it, I changed the fluids to Red Line products. I then changed them again, a couple of years later. The car is now 11 years old, and I'm planning on changing them again. My local oil distributor no longer handles Red Line oils. Would there be any compatibility problems created by switching to Amsoil?

TIA!

 

Short answer is that there will be no problem switching.

From the AMSOIL corporate website: "AMSOIL motor oils can be mixed with other motor oil brands"

Though like most other oil companies, AMSOIL doesn't publish the exact composition of their basestocks, their top tier oils, tranny fluids and gear lubes are commonly believed to contain a Group IV (PAO) and Group V (polyol ester) blend - probably mostly PAO. But adding some polyol ester to PAO has two benefits. One it lowers the overall coefficient of friction, and two it changes the overall impact of the basestock on porous material (like seals and paper blocker rings) as PAO shrinks them and polyol ester expands them. The blend can be made to have a very slight change (helps prevent seal leaks which were common in the early days of synthetics). Red Line uses a polyol ester basestock. So whatever minor amount of polyol ester that remained in your tranny/diff will have almost no impact on the AMSOIL basestock as it probably already has a little polyol ester in it already.

I myself switched my 02 Z06 to Red Line tranny and diff fluid when it had about 800 miles on it. Ran it for many DEs and my first race season in 2003. Switched to AMSOIL in 2004 - no ill effects noted.