Rear end lube-Whats in yours?
11-29-2007, 06:41 PM
#1
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Rear end lube-Whats in yours?
3.42 Borg Warner. Time to change the rear end fluid. What's recommended. Still got a old bottle of the GM posi additive. Do I need it or can I go with some LUCAS or something like that. Thanks!
TJ
TJ
11-29-2007, 06:44 PM
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Car: 1991 RS, 84 El Camino conquista RIP
Engine: 5.0 (for now)
Transmission: 4L60
Axle/Gears: 2.xx torsen limited slip & 3.42 ope
Re: Rear end lube-Whats in yours?
I swear by Lucas and synthetic Lucas if it's a newer car or posi. I liked it but the synthetic was spendy at 10 bucks a quart.
plus you never have to flush it again!
plus you never have to flush it again!
11-29-2007, 07:00 PM
#3
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Re: Rear end lube-Whats in yours?
I only use Mobil 1 synthetic..
My dragster, 3rd gen, my tow vehicle, daily driver, and 67 camaro all have it. I would not use anything else.
My dragster, 3rd gen, my tow vehicle, daily driver, and 67 camaro all have it. I would not use anything else.
11-29-2007, 07:16 PM
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Car: 91 R/S , 89 dodge p/u
Engine: L31 GM crate re-cammed , 318
Transmission: T-5 , 4 speed auto
Axle/Gears: 3.42 , ?
Re: Rear end lube-Whats in yours?
well i have full synthetics in eng. [lo3] , trans. [t5] , diff. [3.08] . daily driver with mild mods. and get 27-29 m.p.g. hwy. . lots of hype on each brand . check bobistheoilguy to compare and decide .
12-07-2007, 06:49 PM
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Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Rear end lube-Whats in yours?
Another vote for Mobil1 synthetic...
Dino oil I run 80/90...
Dino oil I run 80/90...
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12-07-2007, 08:08 PM
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Car: '91 Z28 L98 G92
Engine: Modded L98
Transmission: Modded 700R4
Axle/Gears: Modded 10-Bolt
Re: Rear end lube-Whats in yours?
GM axle lubricant with GM posi additive works best for me. Made the difference between a very, very slight whine (using Valvoline axle lube) from the Richmond gear set I installed to a nice, quiet rear axle. I haven't had good results with synthetic lubricants...at least with engine oil. Bill
Last edited by Burnout91; 12-07-2007 at 08:12 PM.
12-07-2007, 10:13 PM
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Car: 90 Firebird Formula
Engine: LO3
Transmission: T5
Axle/Gears: 3.08 one wheel peel
Re: Rear end lube-Whats in yours?
Believe it or not, my pinon seal started dripping pretty bad. After a few days, I knew the rear end must be low. I filled it back up with valucraft 75w90. Still leaked, but slower. When it got low again, I filled it up with walmart's SuperTech 90w140. Almost stopped leaking. Next time, i only jacked up the right side, and overfilled it a little. It stopped leaking completely and hasnt since then.
My best guess was that the factory fill had thinned out enough where it was like water. The new oil must have thickened it up enough to stop it.
My best guess was that the factory fill had thinned out enough where it was like water. The new oil must have thickened it up enough to stop it.
12-07-2007, 10:51 PM
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Re: Rear end lube-Whats in yours?
i run fully synthetic of every single fluid in the vehicle. iv had best results with mobil 1 full synthetic, and GM "performance parts" has an additive for posi specifically for use with the mobil 1 (since most new GMs actually say "mobil 1" everywhere), but it can take some convincing to get them to admit they have it, since the cars and trucks didnt come originally with synthetic. my 85 'maro is driven hard and put away wet, one more vote for mobil 1
12-07-2007, 11:02 PM
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Car: 1985 Iroc-Z
Engine: 440LSX
Transmission: l460e
Axle/Gears: 3.55 Wavetrac
Re: Rear end lube-Whats in yours?
If you have a OEM diff. the oils suggested by everyone will be fine. Bear in mind that some posi units(Eaton) use only mineral based oils,no synthetics. I have tried to find out why but have gotten no e-mail response from Eaton. I recently installed a new Eaton posi unit and their instructions were to that effect. Anyone maybe know why they only specify mineral based oils?
12-08-2007, 11:29 PM
#14
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Car: 1987 Camaro SC, 1999 Z28
Engine: GMPP 350HO, LS1
Transmission: Built 700r4/EDGE 3200, T56
Axle/Gears: 3.42 Eaton 7.625, 3.42 Zexel Torsen
Re: Rear end lube-Whats in yours?
i was curious to that as well badman. running an aftermarket eaton with lakewood gear oil.
12-10-2007, 03:08 PM
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Car: projects.......
Re: Rear end lube-Whats in yours?
regular gear oil - Strange actually reccomends not running any of the sythetic/magic oils out there. They say they've seen too many rear-end failures due to these supposed "better" lubes.
I think I've got 85/140 in mine...could be 80/90, regular Castrol. No additives here, but tru-track posi unit. - we run castrol 50w gear lube in the 10.5 car.
I think I've got 85/140 in mine...could be 80/90, regular Castrol. No additives here, but tru-track posi unit. - we run castrol 50w gear lube in the 10.5 car.
12-10-2007, 06:10 PM
#20
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Car: 86 T/A & 88 GTA
Engine: 305 LB9 TPI & 350 LO5 TPI
Transmission: Jasper 4L60 x2
Axle/Gears: 2.77/posi LSD & 2.73/posi LSD
Re: Rear end lube-Whats in yours?
i vote for lucas since you need no extra additive and i works great!
03-29-2009, 06:23 PM
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Rear end lube-Whats in yours?
I got lucky last year and a sponsor supplied me with 3 bottles of Lucas 75w90 for the diff.
Race tracks hate the synthetic diff oils. It's hard to clean up when a diff explodes. I saw a pickup truck blow the pinion out of a 9" last year right on the start line. Took a while before they got it all cleaned up.
Race tracks hate the synthetic diff oils. It's hard to clean up when a diff explodes. I saw a pickup truck blow the pinion out of a 9" last year right on the start line. Took a while before they got it all cleaned up.
03-29-2009, 06:52 PM
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Car: 1987 Firebird Formula
Engine: 2004 LQ4
Transmission: T-5 WC
Axle/Gears: 3.42
Re: Rear end lube-Whats in yours?
3.42 BW with locking diff..
AC Delco 75W90 w/ POSI additive. It's like a $50 gear oil change, but it won't ever go bad.
AC Delco 75W90 w/ POSI additive. It's like a $50 gear oil change, but it won't ever go bad.
03-29-2009, 06:53 PM
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Car: 1983 trans am
Engine: Vortec 350 w/ a comp cam
Transmission: B&Mth350 2800holeshot
Axle/Gears: 10bolt 3.23's
Re: Rear end lube-Whats in yours?
i run motorcraft (yes ford) 75/140 synthetic only cause i work at a ford dealer and it was freee!
01-30-2010, 05:59 PM
#26
Re: Rear end lube-Whats in yours?
I was told by a 2 diff shops in New Zealand that I visited that rebuild 9 bolts = M78 Borg Warner all the time (they are in ton of cars in NZ and Australia) to use Redline Edit oil was Redline 75W140 #50304 with NO additive. The cones will bang and clunk a little bit, but this will be totally normal and doesn't hurt anything.
If your cones are worn, use the Redline heavy shock oil, otherwise the normal stuff will do. The additive is a friction modifier or reducer and reduces the effectiveness or grip of the posi unit (cone type).
That's what I run with just under 400HP to the wheels on drag radials with no issues. The cones don't even make much noise..
https://www.thirdgen.org/forums/tran...-use-posi.html
https://www.thirdgen.org/forums/tr...dline+gear+oil (Rear End Gear Additive, Part 2 (9-bolt owners please read!))
If your cones are worn, use the Redline heavy shock oil, otherwise the normal stuff will do. The additive is a friction modifier or reducer and reduces the effectiveness or grip of the posi unit (cone type).
That's what I run with just under 400HP to the wheels on drag radials with no issues. The cones don't even make much noise..
https://www.thirdgen.org/forums/tran...-use-posi.html
https://www.thirdgen.org/forums/tr...dline+gear+oil (Rear End Gear Additive, Part 2 (9-bolt owners please read!))
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