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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: rv_safetyman on September 18, 2011, 09:39:56 AM

Title: Mix Synthetic Differential Lube brands?????
Post by: rv_safetyman on September 18, 2011, 09:39:56 AM
We are on the road and I have a small "leak" in my differential area.  Tried to fix it before we left, but still have a small loss.

When I had to rebuild the diff and dropbox, I filled it with Shell Spirax S (I think it now has an additional letter or two after the "S" designation) fluid (also use it in the service truck that we tow).  I thought I brought some with me, but I guess I left the bottles at home.

Now I am trying to find it on the road (currently in SW Iowa) and it is not readily available from what I can see.  I am doing a  bunch of searching for on-line sources, but they are not jumping out at me.

So, my question is, can you mix GL5 synthetic lubricants?  One source mentions that an equivalent is Mobilelube SHC.

I will be checking on Shell Distributors in the area, but my hopes are not high.

Jim
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: Lin on September 18, 2011, 10:03:40 AM
You could try to call Shell tech support (713 237-8645, option 4 then option1), or the manufacturer of the replacement oil.  Generally, when I have inquired about such things, they say something to the effect that if they meet the same standard, they are compatible.  Although I am not positive they are right, I do not think I have had noticeable problems on the rare occasion I have mixed brands.  Of course, that does not mean that there were no invisible issues.
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: luvrbus on September 18, 2011, 11:08:41 AM
If all else fails pour the Lucas to it Lucas will mix with everything but water

good luck
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: bevans6 on September 18, 2011, 11:28:25 AM
I mix brands all the time.  No problems at all.

Brian
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: eagle19952 on September 18, 2011, 08:12:53 PM
add what clifford said or use a Chevron product,they sell more syn base stocks and additive packages than any other producer.
I believe Mobil is their only major competitor.
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: GMC5303Wonder on September 19, 2011, 06:03:56 AM
As long as it meets or exceeds the specs (2 letter code) of ur needs the brands mix with absoutely no problem.  Just make sure you use the same weight...... you can even use a partial synthetic or a "blend" in a pinch but just remember you'll lose the benefit of having full synthetic lubricant
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: Ed Hackenbruch on September 19, 2011, 07:12:34 AM
 The Lucas may even seal your leak. :)
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: Bill in KS on September 19, 2011, 11:08:44 AM
Just food for thought............... not all Synthetics are made from the same base stock so their compatabilty can be good or bad with other products.  Some Synthetics are made from veggie oil and are ester base ( not very compatable)  but cheaper to produce and the major companies sure charge a lot of $$ for the product on the shelf.   
The less people know and the more they believe what they are marketed on TV the better for the major oil companies.

I'll end on this: Which do you buy more of , gas or oil and grease ???

Certain oil base stocks are a byproduct of making gas and needs to be disposed of, guess what we are sold as " good " motor oil .......... yep , their left overs.  Majors are in the gas business and do a great job of selling use their waste at a premium price with a fancy label. 

Knowledge is power
,
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: rv_safetyman on September 25, 2011, 10:12:29 AM
Update:  I was able to find a Shell distributor that had branches in Omaha and Des Moines.  They were very friendly and helpful.  They transferred a case to Des Moines and one of the family members picked it up for me when they were there for a class.

Yesterday I crawled under the bus and checked the fluid level.  It started out about 1/4 inch down when we left and took about 1/2 quart to top off.  Not as bad as I had feared.

The leak first appeared to be the drain plug (had some damage).  I replaced it and now the leak seems to be between the rear end pumpkin and the housing.  I have tightened all the bolts again and still have some seepage.  Not sure what to do next, but I am good to go for this trip.

I might try to find some Lucas rear end fluid and see if it says anything about "sealing".

Jim
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: luvrbus on September 25, 2011, 10:51:20 AM
Jim, it will help on a seal not the differential probably someone used silicone on the gasket when mating the 2 I never use that crap on a gasket or would never use it mating the 2 without a gasket either like some I have seen

good luck
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: GMC5303Wonder on October 05, 2011, 02:45:41 AM
If it is silicone and you don't have a gasket available..... use a gasket maker called the right stuff.  Sold at all auto parts stores.  On newer vehicles this actually is the gasket used in many applications and is the best sealing silicone/gasket maker out there.
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: luvrbus on October 05, 2011, 04:12:50 AM
If you use a gasket maker use the CAT brand I do carry that along with their liquid o-ring maker 

good luck
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: Just A Newell on October 05, 2011, 05:34:34 AM
Have not used the cat brand, but the right stuff is the goto product around the farm.
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: bevans6 on October 05, 2011, 06:18:01 AM
I use the silicone products on stuff that I don't care if it leaks a bit and that I plan to take apart a lot.  Like racecar gearboxes, we sometimes have to change gears at the track.  I use "the right stuff" for goo if I need it since it's on the shelf most places, but have gone to the Permatex aviation sealant as a gasket dressing.  One little bottle did my 8V-71 project and there is still a little left.  http://www.permatex.com/products/automotive/automotive_gasketing/gasket_sealants/auto_Permatex_Aviation_Form-A-Gasket_No_3_Sealant_a.htm (http://www.permatex.com/products/automotive/automotive_gasketing/gasket_sealants/auto_Permatex_Aviation_Form-A-Gasket_No_3_Sealant_a.htm)

Brian
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: Busted Knuckle on October 05, 2011, 07:09:56 AM
Jim,
Lucus is a handy thing to carry !
It can be used in the rear end, engine and wheel hubs on the road! We keep a gallon of it on the buses for emergencies! (one note it is thicker and slower pouring than molasses!)

My uncle once got some on him while using it and claims "it's the
slickest sticky stuff on earth!"

Now about that leak @ the differential. There is this shop down in Chattanooga that has plenty of experience with stuff like that! Should I look up the address & # for you?
;D  BK  ;D
(actually I don't have to look them up as they are in my permanent memory, phone and gps! LOL)
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: luvrbus on October 05, 2011, 07:31:09 AM
Brian,aviation Permatex (no 3- 5) is all I ever use DD made a huge mistake back in the 80's when they said use RTV on the back plate people still use it as they don't have the service bulletin to upgrade their service manuals DD stopped using the the RTV and went back to gaskets and aviation Permatex never saw a DD put together with silicone that didn't have leaks
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: Boomer on October 05, 2011, 01:16:50 PM
Common differential leak is the studs being loose, should always tighten them before mating the drop in to the housing.  I always use the red Permatex aneraobic gasket maker on the threads, DDC also has a good product.  Torque the studs and nuts to GFT (good and f....g tight), lol.  Another thing I recommend to bus nuts since we don't put many miles on a unit is to seal each side of a componant that is coming off for rebuild or repair.  Common maintenance practice in commercial service is just put sealant on the componant side to reduce clean up but we usually only have to do these jobs once, better to eliminate all chances of a leak.  JMHO
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: luvrbus on October 05, 2011, 01:48:59 PM
That is strange Boomer in the Rockwell school they told us never use any type RTV except the 3-Bond TB 1216 or Loctite 5699 Gray,they prefer a gasket but if you use RTV use those were the only RTV Rockwell approved but the red must have worked for you.

Most leaks I find are caused by people using a .20 cent Ace Hardware washer I had a terrible time with Smith trying to use the cheap washers on the differential case on his bus lol

good luck
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: Boomer on October 05, 2011, 01:54:26 PM
You must have misunderstood Clifford, I always use a gasket and never silicone.
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: luvrbus on October 05, 2011, 01:57:37 PM
I guess I did Boomer didn't sound right to me you using silicone lol

good luck
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: bevans6 on October 05, 2011, 02:06:48 PM
I think Boomer was saying to install the studs with red Loctite stud sealer, which is what I do too.  I use aviation AN washers, they have a couple of different grades and hardened ones if you are putting enough torque on to crush a plain flat washer.  I also use split lock washers made for socket head cap screws if I need a lock washer, they are very tough little guys.  Glad to hear you like the Permatex Aviation gasket sealer!

Brian
Title: Re: Mix Synthetic Differential Lube brands?????
Post by: rv_safetyman on October 05, 2011, 03:41:09 PM
Wow, lots of good discussion.  I decided to wait to reply until I had done more investigation.

First of all, the silicone issue is interesting.  I lost a rear end just before I went on the road in 2006 and installed it myself {fun :o}.  I have tried to remember what I used for sealing.  I am pretty sure I did not use a gasket.   My best guess is that I used "Right Stuff" gasket maker. 

Before I left Evergreen I replaced the bottom plug as the original one was damaged and it looked like it was leaking.  I also tightened the pumpkin bolts (very little to no rotation).  When we got to IA and I got the Shell Spirax, I put about 3/4 of a quart bottle in.  I am pretty sure that it was a bit low before I left.

During our journey over here (Greenfield, OH) we stopped at a couple of Wal Marts and I did not see any puddle.  I just crawled under and checked the level and it is full.  That is after about a week and 600 miles.  Looks like I don't have all that much of an issue.  I will check it a few more times as we travel to Chattanooga and home.

Thanks for all the input.

Jim