I have a TKO 600 with no external coolers/pumps, etc. It has about 4000 miles total on it - weekend/sunny day car only. I have run it pretty hard on the track a handful of times (maybe 6 days over the last 3 years). After the initial break-in, I changed the oil to Valvoline MTF. The manual calls for ATF for the 1st 500 miles, then GM Synchromesh and Valvoline was what O'Reilly had. The bottle says it is compatible with the GM stuff.
Over the last few weeks my tranny has been hard to get into gear. Any gear. (I know, I need to check the clutch disengagement). Anyway, I decided to change the oil. The tranny is known for its notchy shifting and I have a buddy who raves about Amsoil, so I figured I'd try it. When I drained the old Valvoline stuff out, it looked like chocolate milk. It was still pretty thick and I didn't see much particulate material (I didn't look that closely at the time). It didn't smell burnt. I don't have any other fluids that can get in there. No water/antifreeze/motor oil, etc has access to the tranny. It is just a self contained unit. It has not been out in the rain - no way for water to get inside.
Would the residual ATF left in the case after draining, mixed with Valvoline MTF cause a chocolate milk appearance?
I haven't put the Amsoil MTF in yet. I hate to "waste" $20/qt Amsoil if I will need to drain and fill again in xxx miles. Should I fill it with cheaper MTF or other gear lube, run it for 100 miles, then D/F with Amsoil?
Any other thoughts?
MTF drain = chocolate milk
- Thread starter Texasdoc
- Start date
4WD
$50 site donor 2023
Valvoline Synchromesh is what, $10/quart … Can you run one bottle through with plugs out before the AMSOIL?
Redline MTL is also popular for synchromesh applications
Originally Posted by AC1DD
Factory told you GM synchromesh and you used valvoline mtf. which specific product
?
Originally Posted by 4WD
Can you run one bottle through with plugs out before the AMSOIL?
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Originally Posted by Texasdoc
Originally Posted by AC1DD
Factory told you GM synchromesh and you used valvoline mtf. which specific product
?
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TREMEC now makes there own fluid for their transmissions. Give them a call.
I'd use Mobil 1 Synthetic ATF. I see nowhere on their website that calls for MTF of any kind.
https://www.tremec.com/faqs.php
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drain and fill with cheap stuff. repeat until no more milkshake comes out.
fill with the appropriate Redline or Schaeffers product (they are world leaders in gear oils)
I'd say water is finding its way into the transmission. I'd get the spec'd fluid, drain the unit, drive it a bit and repeat. Look for possible water entry points. Then drain and check the fluid condition in a thousand miles. After that keep an eye on it to see if it is changing color after some heavy rain storms. You can do that by extracting or draining a small sample and topping it off.
What vehicle is this ?
I would only the Manufacturer spec fluid for now.
Originally Posted by Mr Nice
What vehicle is this ?
Originally Posted by zeng
I hear you discounting such .
Originally Posted by montero1
I see nowhere on their website that calls for MTF of any kind.
trans-fluid cooler built into the radiator would allow water ingress and mixing if it were faulty. Failed water/oil heat exchangers make people think theyre HG is failing, similar effect is in play here maybe?
I had a pickup with a new venture 3500 transmission that called for gm synchromesh fluid.
The trans was a bit worn out and the shifting was notchy. I tried the Gm fluid, Pennzoil synchromech, and Amsoil synchromesh. The shifting was noticably better with the Amsoil fluid than the other 2.
As far as the milky look, it is normally moisture, although I guess it could possibly be from mixing 2 different fluids.
If there is a vent on top of the transmission, I would make sure moisture isnt making its way in that. Like if there is a vent nipple that needs a hose attached to it, or ac condensate water isnt running down near the vent.
I would probably get some of the cheaper valvoline or Pennzoil fluid, and put that in as a flush and drive it for 50-100 miles to get it hot and dump it. Then install the Amsoil fluid.
OP my Cobalt SS had milkshake MTF when I did the first change around 30,000 miles. That was ten years ago or so. I'm at 150,000 miles now.
I'm not sure what causes it. The OEM fluid is dark red btw. My guess would be moisture easily getting in through a vent, coupled with wear material and just age.
Not being able to go into gear is concerning. Did a fluid change fix that? I'd start by finding out what the proper fluid is for your trans and then doing a drain and fill with that. Check the drain plug magnet for shavings - install one if you don't have one.
I *think* the shifting difficulty is likely the clutch is not fully releasing. It may just need a pedal stop adjustment. I didn't have an assistant to push the pedal to help measure the master and slave throw, I started with the fluid change. Alice took me down the rabbit hole.
I don't know if there is a vent - I'll have to look.
