75W140 vs. 75W90
- Thread starter Garry
- Start date
- Status
I'd like to know that too, although now it's too late to change. I needed to change the gasket on the rear differential on my son's Mountaineer with All Wheel Drive. A metal tag on one of the bolts said to use ONLY 75W-140 Synthetic. Guess who is the only retail vendor of such an oil near me? Ford, of course. $17.45 per quart x 3, plus a bottle of friction modifyer for the limited slip rear. Cost me $65 including gasket and sealant, and I did the work myself.
Why could I not use either 75W-90 syn. or 85W-140 dino? (only alternatives in the 6 or so parts stores in my area that were open the day after Thanksgiving.
Is this stuff sold by anyone other than Motorcraft? I found Mobil 1 75W-90 for $8 per quart.
Why could I not use either 75W-90 syn. or 85W-140 dino? (only alternatives in the 6 or so parts stores in my area that were open the day after Thanksgiving.
Is this stuff sold by anyone other than Motorcraft? I found Mobil 1 75W-90 for $8 per quart.
Well at least you have the piece of mind that the fluid should never need changing again.
If Delo ESI can go for 500,000 miles in a tractor trailer set up between diff drains, you should be quite safe for the next 10 years with your ford 75W140 at 6 times the price.
If Delo ESI can go for 500,000 miles in a tractor trailer set up between diff drains, you should be quite safe for the next 10 years with your ford 75W140 at 6 times the price.
Hi,
I have done lots of experimentation with the heavy & thick synthetics in my 500hp ( 42000kg ) semi-trailers.
Often the heavy oils are recommended for their "shock loading" abilities. Especially at startoff when heavily laden.
I now use 75w-90 Mobil or Castrol synthetic in diffs. This has lowered the general average operating temperatures by about 30C or more.
The avgerage temp. of all is now 90C, highest 102C and lowest 72C. In this country with very high/low ambient temps we knew that the average temp was never going to be higher than 100C with mineral oils. Synthetics have certainly cooled them down and greatly extended seal life
It is a lifetime fill for then - up to 1.3m kms or so
Regards
I have done lots of experimentation with the heavy & thick synthetics in my 500hp ( 42000kg ) semi-trailers.
Often the heavy oils are recommended for their "shock loading" abilities. Especially at startoff when heavily laden.
I now use 75w-90 Mobil or Castrol synthetic in diffs. This has lowered the general average operating temperatures by about 30C or more.
The avgerage temp. of all is now 90C, highest 102C and lowest 72C. In this country with very high/low ambient temps we knew that the average temp was never going to be higher than 100C with mineral oils. Synthetics have certainly cooled them down and greatly extended seal life
It is a lifetime fill for then - up to 1.3m kms or so
Regards
Userfriendly,
Have you pulled a diff cover on one of these after 50,000 miles with the OEM Ford synthetic?
The factory fill synthetic leaves something to be desired in this application. Ask anyone with a powerstroke....
OTR trucks accumulate 500k miles in two years and run under steady state conditions. It's not exactly an apples to apples comparison. You have issues with moisture accumulation and corrosive wear in light truck diffs that you don't see in OTR trucks. When was the last time you saw somebody backing their Triton bass boat down the ramp using a Peterbuilt?
The Delo ESI is good stuff, but what use do you make of the remainder of that five gallon pail when your diff holds one gallon? Not everyone keeps a dozen vehicles scattered about their property. That's good for a "White Trash" notice and fine in the area where I live
FWIW,I think you're really most like a "Cur-mudg-eon"...you need to look that one up!
Happy Holidays!
Have you pulled a diff cover on one of these after 50,000 miles with the OEM Ford synthetic?
The factory fill synthetic leaves something to be desired in this application. Ask anyone with a powerstroke....
OTR trucks accumulate 500k miles in two years and run under steady state conditions. It's not exactly an apples to apples comparison. You have issues with moisture accumulation and corrosive wear in light truck diffs that you don't see in OTR trucks. When was the last time you saw somebody backing their Triton bass boat down the ramp using a Peterbuilt?
The Delo ESI is good stuff, but what use do you make of the remainder of that five gallon pail when your diff holds one gallon? Not everyone keeps a dozen vehicles scattered about their property. That's good for a "White Trash" notice and fine in the area where I live
FWIW,I think you're really most like a "Cur-mudg-eon"...you need to look that one up!
Happy Holidays!
I thought I'd chime in with a bit of info...
I have a 1970 Land Rover that I just recently got on the road after a lenghty rebuild and prior to that a *very* lengthy period of sitting.
In any case, once I got her on the road, it was apparent that the front diff was very noisy. I changed out the cheapo 80w90 that I had in there to flush things out and put RedLine 75w140 in there. Now, the manual specs 80w90, and I was going to put RedLine 75w90 in the diffs, but noting the amount of filings that came out I figured the 75w140 couldn't hurt much as I have no idea how long the diff will last.
She's gone about 400 miles now with the 75w140 and I think I'll check on things after a few more hundred miles...
Bogatyr
I have a 1970 Land Rover that I just recently got on the road after a lenghty rebuild and prior to that a *very* lengthy period of sitting.
In any case, once I got her on the road, it was apparent that the front diff was very noisy. I changed out the cheapo 80w90 that I had in there to flush things out and put RedLine 75w140 in there. Now, the manual specs 80w90, and I was going to put RedLine 75w90 in the diffs, but noting the amount of filings that came out I figured the 75w140 couldn't hurt much as I have no idea how long the diff will last.
She's gone about 400 miles now with the 75w140 and I think I'll check on things after a few more hundred miles...
Bogatyr
Does your rule of thumb include OTR vehicles? They have much larger than 9" ring gears and many are running on Amsoil 75w90 for the fuel savings over the 75w140. Also lower diff temperatures? What are your thoughts on this?
I am running 75w90 Series 2000 in my Excursion front and rear. PIcked up 8% in town and 11% highway better fuel economy with the switch.
MolaKule
Staff member
I have to disagree WRT to the Ford fluids.
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=16;t=000319
My rule of thumb is that if you're pulling or hauling loads in the summer, or if your ring gears are > 9" in diameter, a good synthetic 75W140 or 80W140 is good insurance.
If your ring gear is <= 9" in diameter, then a fluid I recommend is Schaeffer's #267.
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=16;t=000319
My rule of thumb is that if you're pulling or hauling loads in the summer, or if your ring gears are > 9" in diameter, a good synthetic 75W140 or 80W140 is good insurance.
If your ring gear is <= 9" in diameter, then a fluid I recommend is Schaeffer's #267.
MolaKule
Staff member
The rule of thumb was primarily for petroleum lubes and blends/partial-synthetics.
With full synthetics, you could probably use a 75W90 for most applications in cars and light trucks. Now for school busses, 5-ton farm trucks, dualies, etc, 75W140 is needed whether it's petroleum or synthetic.
With full synthetics, you could probably use a 75W90 for most applications in cars and light trucks. Now for school busses, 5-ton farm trucks, dualies, etc, 75W140 is needed whether it's petroleum or synthetic.
Hi,
Molakule - Eaton & Rockwell ( now renamed ) recommend 75w-90 synthetics in their OTR products - as I use in mine at 42500kg.
They are used here at up to 135000kg too in triple trailer road trains on routes with 10% grades, at 600hp, 2800ftlbs and at 50>C ambient temp
Regards
Molakule - Eaton & Rockwell ( now renamed ) recommend 75w-90 synthetics in their OTR products - as I use in mine at 42500kg.
They are used here at up to 135000kg too in triple trailer road trains on routes with 10% grades, at 600hp, 2800ftlbs and at 50>C ambient temp
Regards
It's those conditins why Redline gear oil mandated by Volvo trucks Oz after on-road testing with others soon to follow I hear. RL easily outperforms everything in the heat by a comfortable margin. Cheap insurance!
MolaKule
Staff member
Doug,
Eaton/Rockwell has specked synthetic only fluids for some time, which is why Schaeffer's developed the #740 and #741.
http://www.schaefferoil.com/data/740-741.htm
A rule of thumb is only a general guidline in lieu of manufacturers specs.
Eaton/Rockwell has specked synthetic only fluids for some time, which is why Schaeffer's developed the #740 and #741.
http://www.schaefferoil.com/data/740-741.htm
A rule of thumb is only a general guidline in lieu of manufacturers specs.
Hi,
MolaKule - I did not mean to be offensive in my post and I do respect your valued input here
Yes, Eaton ( Old Co. ) was "selling" the benefits of synthetic gear oil - including the use of 75W-90 viscosity - well over a decade ago and after millions of miles research prior
They were particularly adament that seal life was considerably longer. This is indeed correct in the real world!
Many people do not see the equation equalling low operating temperatures in these applications
even Eaton's Techs here didn't.
Only when we could show them that when constant "shock loading" ( as in tippers etc. ) was NOT an issue and the lubricant could do wonderful things in diffs with inherent high operating temperature problems "their light started to glow". As it had done in their own HO in the USA nearly a decade earlier
Regards
[ December 04, 2003, 08:22 PM: Message edited by: Doug Hillary ]
MolaKule - I did not mean to be offensive in my post and I do respect your valued input here
Yes, Eaton ( Old Co. ) was "selling" the benefits of synthetic gear oil - including the use of 75W-90 viscosity - well over a decade ago and after millions of miles research prior
They were particularly adament that seal life was considerably longer. This is indeed correct in the real world!
Many people do not see the equation equalling low operating temperatures in these applications
even Eaton's Techs here didn't.
Only when we could show them that when constant "shock loading" ( as in tippers etc. ) was NOT an issue and the lubricant could do wonderful things in diffs with inherent high operating temperature problems "their light started to glow". As it had done in their own HO in the USA nearly a decade earlier
Regards
[ December 04, 2003, 08:22 PM: Message edited by: Doug Hillary ]
MolaKule
Staff member
Doug,
No offense taken.
E/R has been one of the more progressive axle manufacturers in terms of seeing the benefits of synthetic gear lubes.
It seems that up here in NA, Dana and others seem to spec 75W140's for anything over 3 tons.
No offense taken.
E/R has been one of the more progressive axle manufacturers in terms of seeing the benefits of synthetic gear lubes.
It seems that up here in NA, Dana and others seem to spec 75W140's for anything over 3 tons.
You can. Now if you got some play, then I would try it for sure.
But'd I'd study TooSlicks post, he hit the dragon between the eyes and now the dragon is dead.. i/e
he is on target!
- Status
