'94 6 speed transmission fluid type?
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Joined: Jul 2015
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From: Washington state
'94 6 speed transmission fluid type?
I went to the auto parts store for MTF to do a flush and they gave me royal purple SAE 5w 30 engine oil. GM sells MTF at a high price, but the guy told me that the royal purple manual(?) States that 5w 30 is the "crossover" point? Is this safe to use in my 6 speed manual transmission?
the Chilton manual states that it takes manual transmission fluid 5w 30 or equivalent fluid, but I couldn't find anything regarding whether these fluids were equivalent to each other or not.
the Chilton manual states that it takes manual transmission fluid 5w 30 or equivalent fluid, but I couldn't find anything regarding whether these fluids were equivalent to each other or not.
Last edited by Socalsalas; Jun 3, 2021 at 11:05 AM.
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I went to the auto parts store for MTF to do a flush and they gave me royal purple SAE 5w 30 engine oil. GM sells MTF at a high price, but the guy told me that the royal purple manual(?) States that 5w 30 is the "crossover" point? Is this safe to use in my 6 speed manual transmission?
the Chilton manual states that it takes manual transmission fluid 5w 30 or equivalent fluid, but I couldn't find anything regarding whether these fluids were equivalent to each other or not.
the Chilton manual states that it takes manual transmission fluid 5w 30 or equivalent fluid, but I couldn't find anything regarding whether these fluids were equivalent to each other or not.
Here on the CF Amsoil MTF gets the most 'nods'!!
What you call 'flush & fill' sounds to be 'overkill'!! Do you have new fill and drain plugs? Are yours removed yet?
Here's a 'maybe' recent/maybe older RP .pdf - you'll see what you were sold as a correct for GM 1052931
http://www.royalpurple.com/wp-conten..._Reference.pdf
Last edited by WVZR-1; Jun 3, 2021 at 11:21 AM.
Drifting
Joined: Apr 2020
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From: Orange, CA
The factory fill was, in fact, a 5W-30 engine type oil. ZFDoc recommends a Castrol 10W-60 motor oil as a replacement for 1052931, and got that information from ZF themselves. This website is formatted poorly so I can't link you directly to the part talking about the oil, but if you search for "Castrol" on the page it'll take you there: http://www.zfdoc.com/faq.htm
That said, there's all sorts of recommendations on the forums over what oil to use. But the short of it is, yes, it's motor oil, and yes, that's completely normal. Do not use gear oil, it is not correct for this application.
That said, there's all sorts of recommendations on the forums over what oil to use. But the short of it is, yes, it's motor oil, and yes, that's completely normal. Do not use gear oil, it is not correct for this application.
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Joined: Jul 2015
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From: Washington state
What you call 'flush & fill' sounds to be 'overkill'!! Do you have new fill and drain plugs? Are yours removed yet?
I'm sort going the extra mile in maintenance at the moment. It's got 116,000 miles and the fluid hasn't been changed, as far as I know. At least not since 94,000 miles, which is when I bought it. I have not removed any plugs or started the process yet, but it seemed like a good idea to do a complete flush of all fluids. I did brakes and replaced master cylinder. The mating surface of the clutch master looks rusted, so figured I would replace master and slave and flush to new fluid. Rear diff fluid is getting replaced today, and if it doesnt take me too long, the trans fluid as well. It may be overkill, but is there any danger in it do you think? If the friction of older fluid in the trans is helping the old trans to keep running properly, couldn't I add a bit of friction compound like in the diff? (Just a thought, I would definitely research it before actually doing it)
I'm sort going the extra mile in maintenance at the moment. It's got 116,000 miles and the fluid hasn't been changed, as far as I know. At least not since 94,000 miles, which is when I bought it. I have not removed any plugs or started the process yet, but it seemed like a good idea to do a complete flush of all fluids. I did brakes and replaced master cylinder. The mating surface of the clutch master looks rusted, so figured I would replace master and slave and flush to new fluid. Rear diff fluid is getting replaced today, and if it doesnt take me too long, the trans fluid as well. It may be overkill, but is there any danger in it do you think? If the friction of older fluid in the trans is helping the old trans to keep running properly, couldn't I add a bit of friction compound like in the diff? (Just a thought, I would definitely research it before actually doing it)
Drifting
Joined: Apr 2020
Posts: 1,925
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From: Orange, CA
What you call 'flush & fill' sounds to be 'overkill'!! Do you have new fill and drain plugs? Are yours removed yet?
I'm sort going the extra mile in maintenance at the moment. It's got 116,000 miles and the fluid hasn't been changed, as far as I know. At least not since 94,000 miles, which is when I bought it. I have not removed any plugs or started the process yet, but it seemed like a good idea to do a complete flush of all fluids. I did brakes and replaced master cylinder. The mating surface of the clutch master looks rusted, so figured I would replace master and slave and flush to new fluid. Rear diff fluid is getting replaced today, and if it doesnt take me too long, the trans fluid as well. It may be overkill, but is there any danger in it do you think? If the friction of older fluid in the trans is helping the old trans to keep running properly, couldn't I add a bit of friction compound like in the diff? (Just a thought, I would definitely research it before actually doing it)
I'm sort going the extra mile in maintenance at the moment. It's got 116,000 miles and the fluid hasn't been changed, as far as I know. At least not since 94,000 miles, which is when I bought it. I have not removed any plugs or started the process yet, but it seemed like a good idea to do a complete flush of all fluids. I did brakes and replaced master cylinder. The mating surface of the clutch master looks rusted, so figured I would replace master and slave and flush to new fluid. Rear diff fluid is getting replaced today, and if it doesnt take me too long, the trans fluid as well. It may be overkill, but is there any danger in it do you think? If the friction of older fluid in the trans is helping the old trans to keep running properly, couldn't I add a bit of friction compound like in the diff? (Just a thought, I would definitely research it before actually doing it)
Replacing the fluid is perfectly acceptable.
Remove the fill plug before the drain plug. You know...just in case the fill plug decides to strip.
Best of luck with your fluid maintenance.
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Buy 'NEW' plugs before you start and like mentioned tell VW Parts Person 'HEX'
From a VW dealer "local" but be sure to mention 17mm HEX - VW changed to a specialty plug later but still offer both
WHT-001-937 should be very likely $6 or less. No VW dealer - I believe Audi will do the same part# sequence.
From a VW dealer "local" but be sure to mention 17mm HEX - VW changed to a specialty plug later but still offer both
WHT-001-937 should be very likely $6 or less. No VW dealer - I believe Audi will do the same part# sequence.
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Joined: Jul 2015
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From: Washington state
Buy 'NEW' plugs before you start and like mentioned tell VW Parts Person 'HEX'
From a VW dealer "local" but be sure to mention 17mm HEX - VW changed to a specialty plug later but still offer both
WHT-001-937 should be very likely $6 or less. No VW dealer - I believe Audi will do the same part# sequence.
From a VW dealer "local" but be sure to mention 17mm HEX - VW changed to a specialty plug later but still offer both
WHT-001-937 should be very likely $6 or less. No VW dealer - I believe Audi will do the same part# sequence.
Another interesting thing, another commenter linked to an article on research done on the transmission, and found that carbon buildup occurred at 15,000 miles and recommended fluid swap every 10-12k to give max life to the trans.
Anyway, I'm gonna get under there and get this done, keep an eye out for leaking, and order those parts for next time. Thanks so much to you all for the quick an knowledgeable responses, you've all been such a lifeline in learning how to work on my car!
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The chilton manual states that it takes a 13mm socket to remove the drain plug, but doesn't specify for the filler plug. I called GM and that part has been discontinued, but the service tech told me to just go ahead and torque it just a bit extra if I notice any fluid leakage. VW does have the part though, and given the manual calls for that fluid to be changed every 30k miles, I think I'll just install new ones next time (they wont arrive till next week).
Another interesting thing, another commenter linked to an article on research done on the transmission, and found that carbon buildup occurred at 15,000 miles and recommended fluid swap every 10-12k to give max life to the trans.
Anyway, I'm gonna get under there and get this done, keep an eye out for leaking, and order those parts for next time. Thanks so much to you all for the quick an knowledgeable responses, you've all been such a lifeline in learning how to work on my car!
Another interesting thing, another commenter linked to an article on research done on the transmission, and found that carbon buildup occurred at 15,000 miles and recommended fluid swap every 10-12k to give max life to the trans.
Anyway, I'm gonna get under there and get this done, keep an eye out for leaking, and order those parts for next time. Thanks so much to you all for the quick an knowledgeable responses, you've all been such a lifeline in learning how to work on my car!
Do you only have the Chilton manual for the car? You need a FSM - in the left pane under my user - drop me an email. I can supply you with a '94 FSM and a GM SPO Parts Catalog.
Last edited by WVZR-1; Jun 3, 2021 at 01:28 PM.
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Drifting
Joined: Apr 2020
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From: Orange, CA
Copper buildup from the synchros, actually, not carbon. Some who use the Redline or Amsoil have reported that the copper buildup was lessened compared to the Castrol fluid, and there have been several reports that ever since Castrol reformulated the oil it has had significantly worse performance in the ZF6. And in fact, Bill himself (ZFDoc) has said that any of the 5W-30 synchromesh fluids will work just fine (I believe he actually referenced Redline by name, but I'm having trouble finding that post again). Since these transmissions are getting harder to repair as more and more parts go by the wayside, it may be worth it to use a service interval shorter than GM's "basically never but 100k miles if you absolutely must" one.
Agreed that owning a Factory Service Manual is a requirement for these cars.
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Joined: Jul 2015
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From: Washington state
Yep, you're right about the copper buildup and shorter interval replacement, that exactly what the article recommended too. I see now, M17 are the bits where its *shaped* like the hex, thank you.
Melting Slicks
Joined: May 2013
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From: Sacramento California
Synchromesh MTF 5w30
ZF S6-40 (ZF6) capacity is 2.2 quarts, change every 15-20k miles.
Pennzoil and Valvoline are conventional, Amsoil and Redline (lightweight shockproof) are synthetic.
I have used Pennzoil before with no issues and currently use Amsoil with excellent results.
Never used Royal Purple synchromax but Lord is it expensive. For that price it should rebuild the transmission while you drive.
ZF S6-40 (ZF6) capacity is 2.2 quarts, change every 15-20k miles.
Pennzoil and Valvoline are conventional, Amsoil and Redline (lightweight shockproof) are synthetic.
I have used Pennzoil before with no issues and currently use Amsoil with excellent results.
Never used Royal Purple synchromax but Lord is it expensive. For that price it should rebuild the transmission while you drive.
Last edited by DGXR; Jun 3, 2021 at 05:12 PM.
Drifting
Joined: Jan 2021
Posts: 1,312
Likes: 383
From: Northern California
Synchromesh MTF 5w30
ZF S6-40 (ZF6) capacity is 2.2 quarts, change every 15-20k miles.
Pennzoil and Valvoline are conventional, Amsoil and Redline (lightweight shockproof) are synthetic.
I have used Pennzoil before with no issues and currently use Amsoil with excellent results.
Never used Royal Purple synchromax but Lord is it expensive. For that price it should rebuild the transmission while you drive.
ZF S6-40 (ZF6) capacity is 2.2 quarts, change every 15-20k miles.
Pennzoil and Valvoline are conventional, Amsoil and Redline (lightweight shockproof) are synthetic.
I have used Pennzoil before with no issues and currently use Amsoil with excellent results.
Never used Royal Purple synchromax but Lord is it expensive. For that price it should rebuild the transmission while you drive.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
Race Director
Joined: Oct 2000
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From: N. Alabama
This explains the need for the GL-3 spec lube. The amsoil tech specs for their lube does list GM 1052931 spec. That is what I use. Amsoil has never let me down in any of my vehicles.
https://www.corvetteforum.com/articl...n-Recommended/
https://www.corvetteforum.com/articl...n-Recommended/
Last edited by SouthernSon; Jun 3, 2021 at 07:08 PM.
Thread Starter
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Joined: Jul 2015
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From: Washington state
I'm so sorry, I was doing the diff as well, and got those sizes mixed up. The diff fill plug ended up fitting a 3/8 hex bit, and what I thought was the drain bolt was actually just a cover bolt. I will be ordering the hex for tranny today.
Thread Starter
Advanced
Joined: Jul 2015
Posts: 61
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From: Washington state
Synchromesh MTF 5w30
ZF S6-40 (ZF6) capacity is 2.2 quarts, change every 15-20k miles.
Pennzoil and Valvoline are conventional, Amsoil and Redline (lightweight shockproof) are synthetic.
I have used Pennzoil before with no issues and currently use Amsoil with excellent results.
Never used Royal Purple synchromax but Lord is it expensive. For that price it should rebuild the transmission while you drive.
ZF S6-40 (ZF6) capacity is 2.2 quarts, change every 15-20k miles.
Pennzoil and Valvoline are conventional, Amsoil and Redline (lightweight shockproof) are synthetic.
I have used Pennzoil before with no issues and currently use Amsoil with excellent results.
Never used Royal Purple synchromax but Lord is it expensive. For that price it should rebuild the transmission while you drive.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
I just have the base model and everyone keeps telling me that 5w 30 engine oil is what it takes... I've got royal purple SAE 5w 30 for it, but haven't done it yet. I just did the diff with master pro 80w 90 with 4 oz of the friction additive. GL 5 grade. Which is a synthetic, aren't synthetics always better? I'm probably just going to call GM at this point
If you're going to call anyone, call Bill Bordeau (ZFDoc), or Marc Haibeck (ZR1 Specialist). They are the actual experts on this transmission for the Corvette.
But just so you know, they're both going to recommend you the same things DXGR and WVZR-1 did.
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From: Washington state
Thread Starter
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Joined: Jul 2015
Posts: 61
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From: Washington state
Fill plug was frozen, so I applied 3 rounds of liquid wrench, drove it to full temp, jack stands as quickly as possible, bang on face of plug with hammer (not super hard), used long ratchet and hammer to shock bolt side to side, used a *low profile 17mm hex socket and longest ratchet I had, used a floor jack to raise ratchet handle. Bolt came out. Tighten both fill and drain plug to 36 ft. Lbs for '94.