Sandrail trans axle lube

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Dec 30, 2024
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I run a highly modified 091 VW bus transaxle with Weddle parts in a sand car with a supercharged Ecotec engine. I chew up ring and pinions, bearings or gears pretty fast. At least once a year. Usually the pinion bearing or main shaft bearings go first. Is there a best addative or gear oil I can run? Last time I put in a bottle of Lucas ZDDP engine break in addative but have no idea if that works in a transmission. It has not blown yet but it’s due for an oil change and I was thinking either more ZDDP, a bottle of liquid molly or a best lube for the extreme conditions. Any suggestions welcome. It’s $1600 to $2800 every time it breaks plus it ruins the trip and it’s a lot of work to pull it out. What would you run in it?
 
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What lube are you using now? You could call Redline and talk with a tech to see what Redline recommends.
 
I run a highly modified 091 VW bus transaxle with Weddle parts in a sand car with a supercharged Ecotec engine. I chew up ring and pinions, bearings or gears pretty fast. At least once a year. Usually the pinion bearing or main shaft bearings go first. Is there a best addative or gear oil I can run? Last time I put in a bottle of Lucas ZDDP engine break in addative but have no idea if that works in a transmission. It has not blown yet but it’s due for an oil change and I was thinking either more ZDDP, a bottle of liquid molly or a best lube for the extreme conditions. Any suggestions welcome. It’s $1600 to $2800 every time it breaks plus it ruins the trip and it’s a lot of work to pull it out. What would you run in it?
Post some pictures of this beast. We like pictures.
 
I’ve run the Redline Heavy Shockproof and it blows up. My understanding is the “shockproof” is just an extremely high level of calcium. Last rebuild I drilled two 3/16” holes thru the internal wall above the main bearing in the hopes that extra oil will run down to the backside of the bearing. The main bearing is the main source of trouble. I filled with what the tranny builder had on the shelf. Lucus synthetic with a bottle of ZDDP engine break in additive. It has about 20 hard hours on it and is due for a change so I ordered NEO 75W90RHD. NEO is supposed to have the worlds best CV joint grease and people sware by it so I’m going to try their gear lube. I just wonder if an additive like molly or ZDDP toit would be even better?
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It shifts like a rice rocket. I run a stage 4 pressure plate with a stage two disk because I fan it like a dirt bike clutch sometimes. That combo works for me along with the worlds best shifter. It slips enough to be easy on it unlike a puck clutch disc. The car may not look like much but Bozer built the chassis and I even run a very trick 1:1.2 steering rack, hubs and tricks from RPB MFG because Bob the owner is a good freind. He hates this company but if Pro-Am makes a shifter that fits your tranny then you are in luck. It shifts like a street bike and with the trial an error perfect clutch set up I can run pretty well without a heavy LS and heavy Weddle/Mendeolia transaxle. See: he does not have race budget money for an LS 7 with Weddle transaxle. 😀
https://www.mckenzies.com/products/...rGXSiymHz4Jtqfkj9Wzff6m3lW3t8bcEaYP2Mcm-TjGPz

https://rbpmfg.net/
 
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Lake Speed jr. said in one of his videos that if you have to add something to the oil, then you are using the wrong oil. I do have two engines that sit for long periods so I will probably still add that German liquid Molly to the oil changes so on very dry start ups they have a little bit of help. I went with a boutique oil for the tranny this time and do not expect miracles. There may be a chance that I can remove the nose cone and use an internal bearing pulled to pull the main bearing out to replace it before it blows. To pull bearing by the book you pull the main shaft. That takes a tranny builder with a lot of knowledge and special set up jigs. I was afraid that the Amsoil severe gear 250 might not flow onto the little bearing enough. I run that in the differential of the tow vehicle, but I was afraid it was too thick for the trouble bearing. The real problem is I run a very low fourth gear that sits in front of the main bearing. It is a lot bigger than stock and shields the bearing from oil. I overfill it as much as I can. Top speed is 88 mph at 6700. That is right where it needs to be, but that big fourth gear is in the way of the oil to the bearing.
 
You have already identified that your 4th gear blocks oil to the bearing.

Wouldn’t it be cheaper to simply change out 4th so that you’re not frying an entire trans every year?

What does the manufacturer of this transmission say about the failures?
 
The manufacture only makes the case, some small parts and ring and pinion. Waddle makes the rest. They used to offer a reinforced center section that held that main bearing and I heard it had some mods that allowed for better oil to it. That is why I drilled a couple of holes in the stock case that I have. Changing out fourth gear is really not an option. Most sand cars are LS powered and we rip around sand bowl after sand bowl. I basically row third and fourth gear constantly. My only real options are to swap in a bigger transmission for about $15,000 or find a magic lube that lets the main bearing live longer.
 
NEO 75W90RHD
NEO was and might still be the brand that many NASCAR teams used as rear end oil. Little known fact.

I would run something unadulterated ....... meaning dont mix stuff.

I have to wonder if your issue is lube related, lube delivery related, or just purely to much power....

Have you tried royal purple?
 
I think the NEO just adds that new form of micro graphite. The old Graphite particles were too big. I have the phone numbers to the oil manufactures scientists and labs but do not like to call unless for legitimate business. They are all helpful and most love to talk and explain. Two that I’ve talked to do not. One is Amsoil. They are very protective of their secrets and I believe their people are under a gag order to not talk outside of the approved marketing. Very structured and professional and that is OK. Royal Puple people I talked to do not seem to know what is in their products, do not care and are rather nasty to talk to. Probably the only oil I won’t buy. Want their number?
 
Liquimoly MoS2 for gears.
Came Amazon last night! I’m gonna call NEO on Monday to get the knod that it is OK to mix with their gear lube. Once in a blue moon certain addatives do no play well together and since this is a boutique racing oil I’m gonna check with NEO.

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Came Amazon last night! I’m gonna call NEO on Monday to get the knod that it is OK to mix with their gear lube. Once in a blue moon certain addatives do no play well together and since this is a boutique racing oil I’m gonna check with NEO.
Nice. I'm using it with Redline MT90 in my bevel box and r. diff on my VW Golf Sportwagen that I do some track days with - I did one tube for each which at ~1L per, it's a high concentration. The other diff oil to look at is from HPL, they do some race car stuff for NASCAR specifically a diff oil that was used by a team, may be worth looking at. Here are a few pics:

 
I almost used that Redline but allways fell for the heavy high shock. I think it was too thick to feed the bearings. We were talking different type front desert car tires the other day to a guy that needs tires. My buddy runs a tire that is perfect for his particular car and I run a Mickey Tompson. Mine is perfect for mine. Reason is I like low rebound damping so I load the rear under throttle and when it comes up fast I can steer with the rear easier. His is mid engine so he steers with the front more. Just like these oils in that what great for us might be bad for the next guy. Good thing we have choices but sometimes the leaning curve requires expense.
 
Have you talked to Sean at Weddle? What do they say the issue is?
The tranny is built with all his parts and is good for 300 hp. I have a little less power but have to beat it. There is really nothing else that can be done and I run (I think) every part and modification they offer but l like your suggestion and will reach out to him. Maybe he can get me that elusive center section I am missing.. This is the real problem. I built this car to be light and nimble and that tranny fits the bill. I have raced and played all sorts of things and even stood on a world cup podium but there is nothing in the world like running high speed banked bowl after bowl with jumps and drifting. Every angle is different and every banked bowl is on a different curve and every changing. I suck at most things but living in a world of 3-D and always knowing which way is up, down, north and south or what angle I am on is the one God-given talent that I have. Others have as well. Most of the guys out there that are fast just buy Funcos or LS cars to be fast. They basically catch up on the straight or easy bowls. I am in my element in those hard bowls and have to drift them to keep up. I run light rebound so I can make the ass feel light and I cut the side scoops off of the paddles so the car drifts amazing. It is all for fun, but it puts me in my happiest place on earth. I do not need a faster, bigger, strong car. I just need faster, bigger, stronger cars to run with. These guys typically have $75-250k in their LS cars with transmissions that are worth twice what my whole car is worth. I run with the fast guys at Glamis except more sideways. I’m close to 1000 pounds lighter than most of the cars I ride with. Car weighs 1980 pounds with 275hp ish?
It’s like being on a 125cc two stroke in a field of 450’s with everybody just trying to go as fast as we can. No passing allowed unless somebody screws up.

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