I have a Hughes TH400 sitting in the garage soon to go in. I called Hughes to double check what fluid to put in. They recommend Type F (from my searches I see this as a bad choice) but Dexron/Mercon is okay too. But then the guy said to stay away from synthetics. I was too shocked to ask why, but I will try and give them another call. In the meantime, does anyone have any ideas? Thanks

TTT

OEMs used to say things like that because they wanted to sell you more of their product when the one you've got now wears out. They're starting to get the message that people don't like that.

For an aftermarketeer to say that, they are either ignorant, or are using friction parts that don't hold well with the additional film strength of the typical synthetic fluid.

Auburn and Eaton also say not to use synthetic gear lube with their products. The reason is their friction plates don't hold as well with synthetic. However, people still do it.

If they're recommending Type F, you might consider AMSOIL Supershift ATF http://www.amsoil.com/products/art.html . The difference between Type F (and B&M's stuff) and Dexron is no friction modifiers in Type F. I'm using the Supershift in my TH400 (edit: not a Hughes unit) with a high stall converter, no complaints.

Because they want you to buy another TH400 in a few years.

The transmission guy we use has pulled apart a few hughes transmissions and says to have found nothing extra special about the soft parts a few of the hard parts were upgraded.

For the record. I just got off the phone with Hughes. The person I talked to seemed much more knowledgeable. He again said no synthetics. They have tested with them and found that the synthetics are just too slippery and cause scoring of parts. He said that good old Castrol Type F is the best stuff. Also, he said to not use Dexron. Interesting. Anyway, off I go to get some Type F fluid.

I would normally consider those mutually exclusive.

I'm not sure how to evaluate what they're saying. I've never had Hughes products, nor do I know anyone who does. But this just sounds completely hokey.

If a company won't back their products if I use synthetic lubes in them, said lubes that have been around and constantly improved over the past 3 decades and consistently shown to reduce friction & wear, reduce power loss, and increase component longevity, I just choose not to buy their products.

Thanks for the warning about Hughes.

Unfortunately I don't have the option of not purchasing their product. I wish I was a little more knowledgeable about transmissions, then I might better understand what they are saying. But I just have a hard time believing that in this day and age someone would forbid synthetics. I guess since they built it I should abide by their recommendations. At least my fluid will be a little cheaper.

Type "F" was required in transmissions that use asbestos in the clutches. 1977 was the last year that asbestos was used in clutches. According to Borg Warner, Raybestos, & Alto, type "F" has apx. 9 - 14% less holding power in dynamic clutches (clutches that are used to change gears, 2nd & 3rd gears). For non-synthetics, Mobil or Aamco Dexron III fluid. For synthetics, Amsoil or Redline are excellent. Stay away from type"F" fluids.

What's your opinion of B&M's synthetic?

I did not know they had a synthetic, but if it is anything like their other fluids, it is somebody else's then they modify it to their standards, I would pass on it.

Pro Built,

I was hoping you'd weigh in on this. So I can pass on the Type F? I really want to fill it with Redline, but this no synthetic/must be Type F thing threw me for a loop. Thanks.

can you get what they said in writing? may help in case it burns up

Since I have been employed at Hughes for 5 years and done business with them since the late 1970's...... I know they did not tell you the warranty would be void if the fluid is not type F.

I am going to bring this thread up to the tranny manager and general manager to be sure that all Hughes staff that answer questions on the phones are on the same page.

Tony

Tony,

That would be helpful. Some clarification on this from Hughes would go a long way. I spoke to two different people there on separate occasions and was told contradictory information regarding the use of Type F and Dexron. I would still love to hear more about the no synthetic issue.
Thanks.

I happen to agree with those reasons as pros for synthetics. But the cons are related to friction materials in clutches and bands.

No need for an "interpreted" warning when it has a sound basis in reasoning.

Pro Built pretty much summed up the reasons for non-synthetic and requiring Type F. That reasoning hasn't been backed up (yet, anyway) by Hughes. Hopefully Crosley4 can straighten that all out.

As stated earlier, Auburn and Eaton also say no synthetic. There is no confusion with regard to them, however (and I know a fellow racer who used Mobil 1 synthetic gear lube in his rear with an Auburn posi, and it would not hold). Since there is more being lubed than just the friction materials in transmissions and rear ends, I will not use any product that cannot use synthetic lubricants. Hopefully Crosley4 can straighten that all out with regard to Huges, because I haven't heard any other complaints about their products.

Since I am employee at Hughes Performance , I had a short discussion with the general and sales managers today.

On this past sunday I emailed the issues brought up in this thread on Synthetic & type F fluids to the GM of Hughes.

Craig ( GM of Hughes) asked that these issues be reviewed by dept managers and up dated guide lines be issued to all sales / tech staff. Craig stated to me that synthetic oil would not be an issue in street use. We have installed Mobil 1 tranny oil in transmissions at our shop per customer requests. This was the reason I posted that the warranty on Hughes products would NOT be void with the use of synthetic oil.

We have seen some of our race customers with BIG hp cars on the drag strip have some RPM flair on shifts when using synthetic fluids. A change to type F stopped the RPM flair. By BIG hp I am talking over 1200 hp ( per the car owner).

Since we distribute transmission products world wide there will be phone calls placed to manufacturers of the friction materials we use ie; Borg Warner, Alto , etc .

We will gather the current recomendations on the fluids to use / not use with their materials.

I hope you folks do not look at this as simply "lip service". If you see a person answering performance tranny questions around the internet with the nick name Crosley , Crosley4 or Yelsorc ( Crosley backwards) that is me. I've answered questions for near 8 years & I moderate a couple of bbs too.

Tony

Thank you. I was hoping that would be the case, and I am now more than happy to purge the "warning" from my neural database.

AMSOIL has been fighting ignorance and prejudice about synthetic lubricants for over 30 years. Although I am neither an employee nor a representative of AMSOIL, I have been using their products for over 20 years and have been a dealer so I can get the product at the reduced dealer price. I get regular updates on their products and some of the misinformation they have to counter on a regular basis.

To re-emphasize the importance of friction modifiers: We're all familiar with "posi additive", which is a friction modifier that allows the friction plates in a posi unit to slip more smoothly against each other when turning. The same friction modifiers are used in Dexron ATF to provide smoother shifts. IF you have a need to keep those plates from slipping as much, such as the 1200 HP application described above, then an ATF that does not include those friction modifiers is in order. The aforementioned Type F and B&M product do not have the friction modifiers, nor does the aforementioned Supershift.

Thanks again, Tony, for setting the record straight. I'm confident your inquiries to your suppliers will yield the same information. And, I hope this information is passed on to your people that answer customer's calls.

It sounds similar to problems motorcycles have when using car based oil. The car oil additive package is too slippery and does not allow the wet clutch plates to work properly, maybey hughes friction material suffers from a similar problem.
IMHO I'd rather flush my tranny fluid yearly with conventional fluid for under $25 a case than drop $100 just in fluids for 12 quarts of synth. Look at how many cars are out there with 100k plus miles that have never even had a fluid change and shift just fine. I just don't believe synth will extend the life enough to justify the cost. Personally I'd be thankful they recommend conventional ATF.

On a side note: I'm not an automatic guy until recently so excuse my ignorange, but i remember in the past hearing of type"f" fluid being used to increase performance because of it's lack of slippage inducing additives. Goes hand in hand with all the shift kits that extend trans life and increase performance by reducing slippage.

There are a lot of unbelievers wearing out their transmissions early out there.

It just so happens I ride a 2004 Goldwing motorcycle. I've ridden scoots for 4 decades

The Goldwing has 1.8 liter , 6 cylinder engine with wet clutch.

With the motorcycles you need to look at the little label usually on the back of the container. If it says: " energy conserving" do not use it in a motorcycle with a wet clutch. The label is an indicator of moly additives.

Next item..... At Hughes Performance we use Alto red friction material and high energy carbon fiber materials. Many companies in this performence market use these materials.

We have revised our suggestions on syn oils used in street vehicles.

The place we have seen problems with syn oils is in high horse power drag race applications. Many of the dragster class racing guys are using 565 cid to 632 cid motors with over 1100 hp on the motor. In these applications we have seen slipage with syn oil use.

Primarily the slippage has actually been in the torque converter sprag. With a spragless type converter that problem is eliminated.

Our R&D guy , Jeff Hughes still likes to see type F fluid used

Not to get off topic, but when I purchased my 9" rear from Currie, the rep told me to stay away from synthetics. "sythentic lube will eat up a 9". Now here is a unit with a Detroit Locker, that, unlike a tranny has no clutches that get affected by the type of lube. Personally I find it hard to believe that a nearly "indestructable" rear can be destroyed by a different lube than recommended? When I asked why, he said " a synthetic will eat up a 9"! So I did what I was told, and ran the conventional lube. Could it be that these companys care about their customers wasting their money on synthetics, as they are 3 to 4 times as much as the conventionals?

Just from talking with other drag racers who've tried synthetics in their rear diffs, they're seems to be a common occurance of breaking ring/pinions. What they were told is the syntehtic lubes in the diffs do not have the shock absorbing ability the normal dino oil's do.

That makes sense to me. I cant come up with any other idea. I still would not run the synthetic anyway.

I had every intention in the world of breaking in my gears with dino oil then swapping to synthetic, but after hearing of guys having troubles when they did the switch I figured any gains (if any gains) just are'nt worth the risks.

For a street car I think they'd be great, but for race cars with decsent hp and shocking the rear end every pass, I too can see how this is plausible.....Myth Busters baby

I agree

to mee if something is too slick it would be because it is preventing contact of the parts so how would that cause scoring



that would be like saying don't use synthetic motor oil cause it's too slick and you will get scoring on your cylinder walls. instead using something that has more friction in it that and allows the parts to rub one another and you won't havewear issues.

I will be honest I might be wrong but I would think that a synthetic oil itself would have some addative in it that makes it absorb shock loads.
isn't that part of the gl-5 rating to have a sulfer addative which helps dampen and absorb shock?

I know it eats brass though real well though but yeah most any oil should be able to help soften shock loads.

and to the person who said something about synthetic oil not being able to handle it as well but yet can undertand it on a race car just not a street car.

wouldn't you think a race car would have a little more shock load on it then the car you are driving now?

Go back and re read what I posted. you musta ben tired and mis interpreted. I said the synthetic's in the rear diff would be fine in a street car since they're not seeing the shock a race car does constantly.

my mistake I'm sorry


still would think though they would have something to coushin them though
will have to check up on that

What synthetic were they using? Blanket statements like that rarely properly cover the bed. Petroleum rarely matches up to a quality synthetic, but the "me-too" synthetics might be causing trouble for everyone.

forgot about that heinz there are the real synthetics like redline, mobil 1, arseoil and such

but then you have the OTHER "synthetics" like castrol I think is one of them that uses dino juice that just gets refined enough that it can be called a synthetic even though it isn't truely a synthetic.

2 for sure were with Royal Purple, the others are brands I cannot remember, but typical garden variety shelf stuff.

Just a little input on this topic guys.
I work for an ISO class commercial gearbox repair facility and have first hand info reguarding synthetic lubricants being labled a BIG no-no in any gearbox that utilizes a sprag or roller clutch such as an automatic trans does.

Sprags rely on a calculated amount of friction in order to function and the synth is simply too slippery.

I do not profess to be an automatic trans expert by any means but this sprag/synth info is solid and comfirmed in industry.

OH SH IT! I just switched to synthetic after losing 2 rear ends. The pinion had 7 out of 8 tooth fractures. I was hoping the synthetic change would help. Guess I'd better get it back out.

Most pinion tooth failures in a spiral bevel or hypoid gear setup is related to improper tooth engagment (pinion depth & backlash).

Improper tooth engagment is a direct result of parts wear allowing the proper engagment to be slowly lost over time OR, the gears were not set up properly to begin with.

Of course, this is provided that the ring gear diameter is adequate to handle the power applied to it (hence the crappy little 7.5" 10-bolt rears spilling their guts all over our highways).

I set my own rearends up. Setup was per richmond specs. The set I have in there now is within .001 of there spec. The fractures or cracks have a small chip on the front side of the pinion on 2 or 3 teeth, right where it engauges the ring gear. No damage to the ring gear at all. I'm going to send it back to richmond to see what they say.

That is not the case, they say that because they have contracts with oil companies that supplier there oil to them. In most of these contracts the oil companies have to the OEM's recommend there product as the desired brand and type. For example, LS1 & LS2 require Mobile 1, Volvo recommends Castrol even though Castrol does not make that great of engine oil.

OEM's don't want there products to break that gives a bad reputation for the brand.

How did you establish the mounting distance for the pinion?
When you took a pattern (hopefully you did), where was the contact area on the pinion ?

I set my gears up with a depth mic and the back lash with a dial indicator. The set that had the fractures was set .008 back lash. The new set was set .004 deeper with a backlash .006 as the gears are marked. The pattern looks real good, but so did my other set. The rear end that is in my sons car has 2 seasons on it, but that was footbraking and running 7.00s in the 1/8 in a 3000 lb. car. It is now in a 406 Pontiac powered 2nd gen. leaving at 3000 on a brake. It runs high 7.50s. Stock axles and all. I really want to put that 406 in my GTA, but I just can't make myself cut it up for a race car.

I was thinking even futher back. But, you're right, that is the case now.

I've heard of synthetic engine oil being blamed for flat tires. Most of the "warnings" are wives tales. As for sprags, I've never heard that one, but since synthetics are used in everything from factory stock transaxles to modified racing transmissions to Allison trannies, something still doesn't sound right there - at least it's too generalized.

I'll take wear reduction and higher temperature capability over any problem I've heard yet.