OEM LSD versus aftermarket

[Workaholic]

Ok, so first off here's my issue. i've got a whining in the rear end that with it being an 04 i'm pretty sure is a wasted C-clip. What I would like to do is switch from the current open to an LSD and MAYBE even some 4.10 gears while i'm in there fixing all of it.

Anyone have any thoughts of how good the factory LSD diffs are? I dont have any intentions of going FI for power. honestly the biggest "power mod" I want to do is HO cams. Beyond that just regular bolts ons.

I know something like an auburn is going to be better, but I recall hearing that the OEM units still are prone to this C-clip issue. is that true?

I may pull the cover just to inspect everything and see whats up but honestly , gear oil is expensive . Based on that the whining increases with speed, not direction and is pretty constant from about 15mph on i'm pretty sure i've got at least 1 or 2 bearings that need replaced.

Any input would be greatly appreciated.

thanks,
Tom

 

[Catchin Zs]

The c clip issue is true from what I've heard and the OEM LSD's are junk. An aftermarket will perform far better. Detroit trutrac is probably the best out there.

 

[Catchin Zs]

The c clip issue is true from what I've heard and the OEM LSD's are junk. An aftermarket will perform far better. If you're going to swap gears, might as well put an lsd in there so you don't spend another few hundred another time on install. What gears are you coming from? Also, the Detroit trutrac is probably the best out there.

 

[Workaholic]

The c clip issue is true from what I've heard and the OEM LSD's are junk. An aftermarket will perform far better. If you're going to swap gears, might as well put an lsd in there so you don't spend another few hundred another time on install. What gears are you coming from? Also, the Detroit trutrac is probably the best out there.

Currently the truck is 3.92 open. Definitely want to put in an LSD, just looking at my options as a factory unit is quite a bit less BUT i've read a few times now that they aren't really worth much. I would like to go with 4.10's for gears, a nice bump in the low end but now loose my highway driveability and MPG much

 

[TheSatinPumpkin]

3.92 to 4.10 not worth it imo.

Swype-n from my Galaxy Note

 

[Catchin Zs]

IMO it isn't worth it to go from 3.92s to 4.10s, spend that money elsewhere like an aftermarket torque converter which will rid of the power robbing oem one. If you're gonna swap gears, go with 4.56s from 3.92s.

 

[Hemi450hp]

Like mentioned, the factory unit is ok if you can get it cheap enough. If you want to ensure that you dont have issues down the road, I would look into the Auburn or Detroit units. With you being a 4.7, I think you will benefit greatly from a set of 4.56's unless you do alot of highway driving over 70mph...if so, mileage will suffer with the 4.56's.

 

[Workaholic]

Like mentioned, the factory unit is ok if you can get it cheap enough. If you want to ensure that you dont have issues down the road, I would look into the Auburn or Detroit units. With you being a 4.7, I think you will benefit greatly from a set of 4.56's unless you do alot of highway driving over 70mph...if so, mileage will suffer with the 4.56's.

Well it looks like I might be going that route. just found a opened package but not used truetrac, 4.56 gears and a mag hytec cover for $500 local..... gonna call on it when I get home from work and see if I can scrounge the money up in time.

Typically I do my highway driving about 70mph. How bad do you think it will kill mileage? If I keep it to 60 think it will effect it?

 

[TheSatinPumpkin]

What's your tire specs?

Swype-n from my Galaxy Note

 

[Hemi450hp]

That is a steal for those parts. If you are worried about the 4.56's being too much gear, then you could sell them easily and just pick up a set of 4.10's. You are going to need a new bearing install kit as well.

 

[Workaholic]

What's your tire specs?

Swype-n from my Galaxy Note

245/70/17 front 265/65/17rear

 

[Workaholic]

That is a steal for those parts. If you are worried about the 4.56's being too much gear, then you could sell them easily and just pick up a set of 4.10's. You are going to need a new bearing install kit as well.

Exactly my thought. Figured i would pick up a master install kit And replace all the bearing im in there as i wont know whats worn till i crack it open.

Thanks!
Tom

 

[Hemi450hp]

I think you will be happier with the 4.10's. With 4.56's and your tire size out back, you are going to be turning well over 2000 rpms at 70mph.

 

[Ramunit]

I've been hitt'in my stock LSD unit hard since 2005 with zero clips issues or any problems.

 

[Hemi450hp]

Thats the problem with them. They are very hit or miss. I beat the crap out of mine on my 03. Hundreds of burnouts at the track and at least 300-400 passes down the 1/4 mile...not to mention my aggressive street driving, and I never had a problem. Then there are guys who blow them up after a single burnout. If someone already has a factory limited slip, I dont see any reason to replace it unless you know that it is going out. If someone has an open diff, and wants a limited slip, you are much better off going straight to a better built aftermarket unit.

 

[TheSatinPumpkin]

RPM at 70 (OD)
4.10 = 2118
4.56 = 2356

245/70/17 front 265/65/17rear

 

[TheSatinPumpkin]

x2. My oem LSD and clutch retainer clips was perfect at 120k before upgrading to Auburn. What may break with a few miles on one vehicle can run a few hundred k on another.