Check/Change Rearend Fluid

[Archive]

If anyone is getting a few miles on their truck and haven't checked the rearend lube, I'd strongly recommend doing it by 30k-50K miles.

I popped the rear cover on mine today at 51,507 miles and the oil was very dark and filthy. Looked wasted! The gears and insides were covered with a substantial layer of black crud. The magnetic fill plug had at least 1/16" of metallic deposits on it. Appears to have overheated at least once. Hopefully the wear is not excessive but I'm very glad I did the oil change. The virtues of a Mag-hytec rearend cover w/temp sensor are very apparent, which I want to install before serious engine BOMBing occurs.

I cleaned the cover, sanded and repainted it black while I was at it. Refilled with 4 quarts of Mobil 1 75W90 synthetic gear lube.

For anyone putting serious HP to the pavement, I'd check into this by 30k! The lube was only $5. 50/qt. through a Mobil distributor (not much more $$ than standard lube!). Extra protection for cheap, IMO!!

------------------
Vaughn MacKenzie

1998 3/4T QC 4x4 Longbed, 24-valve 5-spd, White over Driftwood, Leather & Loaded, foglights, airdam, DeeZee Running Boards, K&N air filter. 51,420 miles (11/20/99)




[This message has been edited by Vaughn MacKenzie (edited 11-22-1999). ]

 

[Archive]

Vaughn,
Is it a LSD? Did you remeber the additive?

------------------
96 Long bed EC, Banks Twin Ram, BD TC, BD EB, BD VB, Mag Hytec Pans, Warn 8000# winch, TJM Bull Bar, Speedliner, Katzkin Leather kit, K&N Filter, Trailmaster 2" Lift, 35BFG ATKO's, Kodiak Sidewinder Steps, Reflexion Cowl Hood, Autometer Guages, Horton Clutch Fan, PIAA Superwhites.

 

[Archive]

I changed my diff oil at 30,000 miles. It was pretty black and full of all kinds of crap. The magnetic thing was also covered with a lot of deposits and stuff too. My guess the next time I change it it will be much cleaner since all of the breaking in is done. Tips of advice to anyone planning on doing it...

*** Prop up front end of truck on a couple of ramps to make sure all of the oil drains out of the pumpkin.

*** Change the oil when it is warm, not hot... Makes it flow out easier. Gear oil is very think stuff when cold!!!

*** Don't forget LSD additive. Very important, if forgotten, the rear end will chatter and not function properly.


Do it at least every 30,000 miles, more often if you tow. And be sure to inspect the gears for uneven wear on the teeth.

I'll be adding a Mag-Hytec cover the next time I change my gear oil. Not only do they increase oil capacity, but the look really cool!!! #ad


BOMBING UNDER THE PUMPKIN




------------------
Evan A. Beck

98. 5 2500, 4x2, RC, ISB, A/T, SLT, 3. 54 LSD, Trailer tow, Aux. suspension, Forest Green/Driftwood, 44,760 miles, 11/21/99

4" Exhaust split into duals, with 4" x 20" chrome tips one on each side after the wheels, Jacobs E-Brake, K&N Filter (Scotty style), Auto-Meter Ultra Lite boost & pyro, turbo silencer ring removed, OEM foglamps, OEM roof marker lights, OEM 1-ton tailgate marker lamps, Sylvania Cool Blue® 9004 headlamp bulbs, Husky diamond plate toolbox, Line-X spray-in bedliner, plus other cosmetic modifications

"I'd Rather be RAMMIN' than STROKIN'"

"Journeyman B. O. M. B. Member"

 

[Archive]

What type of sealant did you use when you reinstalled the cover? I had checked my fluid last week and it looked pretty nasty so I'm preparing to change it now. Just been concerned about getting the seal right.

------------------
Alan

 

[Archive]

In addition to Evan's suggestions, I also like to change the gear oil at around 100-200 miles on a new or rebuilt differential (new gears, bearings etc. ). It has been my experience with differentials that I have rebuilt that most of the break-in wear will have taken place by this time. In addition, I like to raise the end of each axle (separately) to allow the gear oil to fully drain. Make sure the differential is level prior to refilling with gear oil, using a high quality synthetic.

------------------
'98. 5 2500 QC 4x4, (Black) SLT Sport, personalized license plate: BLCKOUT, ISB, LWB, 3. 54 LSD, A/T, 275 hp. injectors, Glasstite Vision II "canopy", Line-X bed liner, 285/75R16 BFG A/Ts on 16x8 M/T Challengers, Warn 4X Boards, Mopar fender flares, front and rear NW Custom stainless steel/rubber mud flaps, Mag-Hytec diff. cover and trans. pan, Edelbrock IAS shocks, VDO Vision gauges, PIAA Dual Sport 900 auxiliary lights and Super White bulbs, BD exhaust brake and TorqLoc, Prime-Loc fuel filter relocation kit, and Banks exhaust.

SVP of BOMB! heh,heh,heh

 

[Archive]

Is it necessary to add an additive with a good synthetic fluid for a LSD? I didn't think it was.

 

[Archive]

After changing a few rearends in other vehicals I'm a firm believer in changing those fluids.

------------------
98. 5 SLT 4x4 5 spd Quad-cab w/ Mopar running boards with side steps and Grant XL mounted in the ex-cubby holder.

 

[Archive]

I have a question. If the vehicle is 4X4, do you need to service the front as often as the rear.
Arlan

------------------
1998. 5 QC 3500 4X4 3. 54 Auto ISB with all options. TST PowerMax1. BD/TC and Valve Body. RV Injectors, 9000 LB Warn Winch, Ultra Board Running Boards, Westach Combo Boost/EGT and Transmission Temperature gauges, Pac brake GPS etc. etc.
1946 Mercury Coupe Street Rod
1955 Willys Station Wagon
1995 Lexus SC400

 

[Archive]

To answer your questions, no, I do not have LSD. There is a toothed wheel bolted to the ring gear, but this for the ABS speed sensor. I believe it would be fine to put synthetic lube in LSD units but you must add the friction modifier.

I did not use a gasket on the cover, there wasn't one in the first place. I used RTV Blue silicone and I'll let everyone if this seals good or not. No leaks this am. You must be diligent and thoroughly remove all old material and clean the mating surfaces with a non-residue solvent so there is no oil film whatsoever. I used a solvent designed to clean/prep a surface for painting. THEN, apply a good bead (but not too thick) of silicon (being sure to circle all bolt holes) then immediately slap it on and torque it down. I let it set 3-4 hours to cure somewhat before refilling.

I found that brake parts cleaner works great for softening up the old gasket material then steel wool rips it right off. Also I blasted the innards with the brake cleaner to wash out the residue & crud in there, worked great. And lastly, I have a handy electric suction pump which I used to suck the remaining puddle of gook out of the small reservoir in the bottom.

 

[Archive]

On a 4x4 you may as well do the front diff at the same time. On all my previous(4x4) trucks I got into the habbit if changing front and rear diff oils every 20k miles because I off roaded the trucks in water(some river,some ocean)and at the sand dunes alot. 4-Wheeler magazine said water can get in when the axles are turning,that's why I'd change both. I use lots of brake parts cleaner to wash the crud out,but I prefer the Ultra Grey RTV. I like the texture and sealing of this stuff better. So far I've only off roaded this truck a few times,so I may try the synthetics.

-Mike

------------------
99 QC2500 4x4,5spd,LWB,
LSD,3. 54,Amethyst,Agate, SLT,Fogs,Camper,Trailer, Slider,MidlandCB,2wd-low,
Smittybilt bars,Y2k alloys,Straight pipe 3",6-disc Clarion changer,No silencer ring.

Disciple of BOMB
"RATTLE & HUM"

 

[Archive]

One little tip: Put a rag over the gears while you're scraping off the old gasket material to keep the crud from dropping down inside there.
Andy

 

[Archive]

I just receved a reply to an e-mail I sent to Mag-Hytec regarding the availibility of a cover for Dana-60 front differentials.

"Hello;
We are working on the prototype and it may be ready in Feb. give us a call then
Thanks for the E-mail
Roy @ Mag-Hytec"

Now we can have the same convience on our front diff as the rear. Plus the added bonus of looking good both coming and going.

Michael



------------------
'00 Black Sport 3500 4x4 QC, SLT+, 6-Speed, Camel Leather, Trailer Tow Group, Camper Special Group, 3. 54 LSD
'96 Harley Davidson Heritage Softail Special FLSTN
'99 Wells Cargo 2-Place Cycle Wagon 12' x 7'

 

[Archive]

Vaughn, I drained and cleaned out the rear diff area at about 20K, refilled with Amsoil 75-90. I used black silicone to seal the cover, this eliminates any contrast with the black axle housing. How about the manual trans? You guy draining that to? I refilled the trans with Amsoil too. This is manufacturer recommended maintenance on some vehicles. The speedy oil change outfits would like to perform these chores for you although they just suck the oil out, I explained that I wanted to clean the goo off the bottom and be able to inspect the workings. Then I got that deer in the headlights thing.

------------------
3/4 ton, 5 sp, lsd, 2wd, qcab, guages, Scotty sys. Rhino liner, Blue Box hp enhancement

 

[Archive]

Those of you that changed the diff fluid,and switched to a synthetic,are you experienceing any seal leakage do to the different chemistry of the synthetic oil? I heard the change will cause the seals to leak. Also I see that RedLine differential synthetic gear oil already has the additive in it for the limited slip axle.

------------------
97 Ram 2500 Driftwood 5spd 3:54 E-brake Isspro,boost&pyro guages

 

[Archive]

Changed mine @ about 30k- used Amsoil 75-140 and the silver (grey) RTV-no seal leaks so far. Also, while I had the cover off, I drilled it and installed a NAPA drain plug assy. (made for auto transmission pans, but fit the axle cover fine).

------------------
Bill Lins Wharton, TX
98 2500 QC 12v NV4500 3. 54 LSD Manik grill guard Reading aluminum utility body & rear bumper
PHI RAMMA JAMMA

 

[Archive]

TomF1, I live on the Pacific coast where we have a large seal population and I have observed no change (leakage) in their behavior as a result of replacing the oem lube in my diff with synthetic.


Sorry Tom, couldn't help myself.

------------------
3/4 ton, 5 sp, lsd, 2wd, qcab, guages, Scotty sys. Rhino liner, Blue Box hp enhancement

 

[Archive]

TomF1, one of the many reasons I went synthetic was in hopes of prolonging seal life. I've read posts about seals on components where synthetic lubes were used, and pliability was improved and leakage wasn't a problem.

HVAC, at 20K, how did your transmission lube look? I think I'll change mine but was going to wait, according to my owner's manual (on my '98) the 5-speed comes with 75W85 synthetic lube from the factory.

Also, what about the transfer case? I think changing to synthetic ATF is the way to go. 50K miles is a good time just to do all fluids, bumper-to-bumper. Going synthetic would improve protection in the winter and improve mileage as well.

 

[Archive]

synthetics and seals have been a concern for myself , i used mobil 1 634 (140W) in gearboxes on the antenna i maintain at work , switched to the synthetic because the mount would get down to 40*F in the winter and the standard 140W would turn into grease , i had teflon taped all the threaded ports and the input shaft used a carbon face seal that is the same as used on the output rotor shaft of helicopter engines , let me tell you those boxes leaked everywhere , after the last seasonal change to regular lube i haven't changed back since , now i have a 55 gallon drum of the stuff i don't know what to do with , this experience has given me a bad taste for synthetic lubes , is it jusyt mobil one or am i still parinoid ???

------------------
John W. in N. H.
==================================================

Y2K on order, D status schedule build date 12/3 2500, SLT+, Quadcab, 4x4, CUMMINS, Auto, 3. 54 LSD, Driftwood, Camel Leather and LOADED, aspiring to B. O. M. B.

1969 Dodge Superbee, Black on Black, 383, 4spd

 

[Archive]

Mopar Muscle: synthetic lubes do not destroy seals. The seals were probably old and brittle prior to the introduction of the synthetic lube. One of the major attributes of synthetics is their high detergency levels. When old petroleum lubes are replaced with synthetics, the sludge and buildup deposits are washed away, leaving behind deteriorated seals and/or gaskets that were actually creating false seals. I've witnessed this numerous times.

Depending upon the synthetic gear lube manufacturer and formula utilized, along with the condition of your limited slip differential (age, how it was setup etc. ), you may or may not need additional friction modifier with your LSD. I'm using Red Line's 75W140NS(No Spin) gear lube in my rear differential. There is NO friction modifier in THIS PARTICULAR Red Line gear lube formula. I had to add Red Line's synthetic friction modifier in incremental amounts to achieve the desired LS characteristics that I required/desired. Dave, a tech. at Red Line told me that new Dana 70 and 80 LSDs typically require between 6% and 8% friction modifier. I'm currently at just under 8%. Far and away the most popular Red Line synthetic gear lubricant is their 75W90 which contains (for most applications) the correct percentage of friction modifier. I'm using this in my front differential.

------------------
'98. 5 2500 QC 4x4, (Black) SLT Sport, personalized license plate: BLCKOUT, ISB, LWB, 3. 54 LSD, A/T, 275 hp. injectors, Glasstite Vision II "canopy", Line-X bed liner, 285/75R16 BFG A/Ts on 16x8 M/T Challengers, Warn 4X Boards, Mopar fender flares, front and rear NW Custom stainless steel/rubber mud flaps, Mag-Hytec diff. cover and trans. pan, Edelbrock IAS shocks, VDO Vision gauges, PIAA Dual Sport 900 auxiliary lights and Super White bulbs, BD exhaust brake and TorqLoc, Prime-Loc fuel filter relocation kit, and Banks 3. 5" dia. exhaust.
COMING ATTRACTIONS: Banks (ISB) Stinger 4" dia. stainless steel exhaust system!

SVP of BOMB! heh,heh,heh

 

[Archive]

I just installed the Mag-Hytec rear end cover and Lubrication Engineering LE-607 90w oil.
I talked to LE after Roy said he was changing to the LE-607 product.
The specs are great on the oil and the man I talked to was very knowledgeable about oils.

The Mag-Hytec cover look GREAT. #ad


------------------
2000 3500 Quad Cab, SLT+, LSD, 4x2 Auto, 3. 54, Camper Option, Trailer Option, Sports Option, Sliding Rear Window, BLACK. With Power Bolt Tailgate Lock, Dodge Sill Guards, Mag-Hytec Rear End Cover, Leer Camper Shell.