Rear LS in front axle?

BURNSTOUGHFORD · #1 (**permalink**) 11-06-2009, 03:42 AM

I have been considering putting a locker in the rear of my truck and thought maybe the LS from the rear would go in the front axle. I know its revers cut gears and all, but would the LS unit really care if its rotating backwards?

Im thinking it wont. Would be pretty sweet and help in snow/ icy / muddy conditions to have all 4 turning for me.

Bobby82490 · #2 (**permalink**) 11-06-2009, 05:50 AM

I dont know what the differences between the front and rear 8.8s.... I wonder if the LS will work with the front axle disengagement? If you were able to do this, your front driveshaft would turn all the time and the front axle disenagement wouldnt work as it used to.

Big Greenie · #3 (**permalink**) 11-06-2009, 12:29 PM

I also think you would probably give up the front driveshaft disengagement in that kind of carrier swap. That in itself shouldn't be too awful because the Expys do not have the disconnect due to the TOD t-case. My front driveshaft and axles turn all of the time.

What I would like to dispell is the notion that you are going to gain something by fitting a factory LSD to the front. They are pretty worthless, IMO, when in the back, and aren't going to be much better up front. The ONLY way to have all four turning for you is front and rear lockers. LS diffs are nice on road but worthless off road. For the front you need a selectable locker like an ARB. It is going to seriously affect your ability to steer. My other concern would be that you most likely would blow the front CV's. I doubt they are stout enough to take a whole lot more torque than you put through them now. My opinion is that fitting a LSD up there, if it is even possible, wouldn't be worth the hassle. If you go full lockers, remember to use a light foot or risk breaking parts.

BURNSTOUGHFORD · #4 (**permalink**) 11-06-2009, 04:03 PM

Lol thanks for the concern. LSD would work amazingly in the front axle. As for conditions as i mentioned. But a limited slip would greatly improve the front axle when you only have 1 wheel in bad conditions up there, same as it does in the rear. Its not a locker i know and its not intended to be.

But the unlocking front axle would be an issue, there has to be away around that. Im going to need to do more research.

Big Greenie · #5 (**permalink**) 11-06-2009, 04:59 PM

Quote:

Originally Posted by BURNSTOUGHFORD

Lol thanks for the concern. LSD would work amazingly in the front axle. As for conditions as i mentioned. But a limited slip would greatly improve the front axle when you only have 1 wheel in bad conditions up there, same as it does in the rear. Its not a locker i know and its not intended to be.

But the unlocking front axle would be an issue, there has to be away around that. Im going to need to do more research.

It would work amazing well huh? You know this how?

Try out your LSD in back, one wheel on snow covered grass, one on pavement some time. Now floor it and tell me how well it works...NOT!

Sorry dude but your response shows an utter lack of experience with this stuff. Good luck with the swap though, whatever makes you happy.

We could save you the trouble though...how about you give me $1000 and I kick you in the nuts. The results will be the same.

BURNSTOUGHFORD · #6 (**permalink**) 11-06-2009, 05:46 PM

a well setup LS can provide a decent amount of traction. As well as you are always applying some force to the wheel thats not spining even if the LS breaks free. Unlike an open setup, almost all of the power is put to the free wheel. Its has to do with the spring tension on the clutch packs.

I dont know what you do or dont know bud, im not going to speculate. But you do come across as an idiot for assuming that i dont know what im talking about.

Heres a vid of my LS holding up on gravel and pavment in a burn out. Its just to provide some extra traction, not to be a super off road truck

BURNSTOUGHFORD · #7 (**permalink**) 11-06-2009, 05:50 PM

Also i wont do a swap if i have to loose my lock out CVs. As that would greatly decrease the gas milage of the truck. As you would know with your expedition.

I have heard the AWD (part time...not sure what it is) version gets pretty poor when compared.

steve(ill) · #8 (**permalink**) 11-06-2009, 08:18 PM

i would not spend the money to put the LS unit in the front, dont even know if it will fit. to Greenies point, saying a LS unit is worthless is completely false. I have a steep dirt hill that i can climb up in 4 x 4 at about 5 mph without slipping a tire. I can get a run at 25 MPH in 2 wheel drive and it will slip 75 ft up the 300 ft hill. there is a drastic difference. I mistakenly pulled a vacuum line off the front alxe while working and lost the front lock in. for a test, i lifted the front drivers wheel 2 inches off he ground, started the motor and put truck in gear. with the 4 x 4 engaged, the front tire would jump an inch , then lock and stop, then do it again, it was tied to the three wheels on teh ground and would not freely spin. dont know about yours, but miine works VERY good.

galaxie641 · #9 (**permalink**) 11-06-2009, 09:19 PM

Another vote for factory LS working just fine. If it is no longer working the clutches have worn out and it needs to be rebuilt. Just two days ago I pulled my Bullitt in the garage, both tires were in slushy snow on ice then only one was, the car stumbled for split second while the tires dug down in the slush then caught and drove right in. My '51 F3 and '72 F250 with no LS will do absolutely nothing but get stuck in the same conditions. FWIW my TC was off in the Bullitt when I pulled it in, probably wouldn't have even dug in if I left it on.

BURNSTOUGHFORD · #10 (**permalink**) 11-06-2009, 09:51 PM

Spend money fellas? I do all my own work and have a junk yard of 97-01 f-150s at my disposal for next to nothing. ( my cousin has been doing builders since the model came out) Its more of an experiment and should deff help with providing some extra traction.

Thanks for jumping in as well fellas, i know LS isnt the ultimate but its better than nothing. Which was my point in the original question.

Thanks again

Also I think that Greenie was a bit harsh assuming i know nothing about these trucks. Consider the fact that the only part of my truck i have never had apart is the front axle and transfer case. I have built my truck from the ground up and have matched parts from many other years trucks and done several component swaps to make my truck what i consider better.

Big Greenie · #11 (**permalink**) 11-07-2009, 07:29 AM

Is that why you run a 5.4 in front of a 4r70? Or have an 8.8 axle behind a tuned 5.4? I admire your interest in improving your truck. It just doesn't seem all that well thought out.

So do you know what is going to happen to your steering if you fit a tight enough LSD to make a difference up front? I have owned half a dozen or so trucks with front lockers and known several people who have tried a front LSD. They were all removed again once tried, but best of luck.

You wont loose any milage, the CV axles alredy turn in your truck, just the driveshaft gets disconnected at the diff. My 99 F150 4x4 ext long box with the same gears and on size smaller tires actually gets a little worse milage than my expy.

Sorry to offend, I just love the "nuts" line. Couldn't help myself yesterday

BURNSTOUGHFORD · #12 (**permalink**) 11-07-2009, 08:00 AM

8.8 is a very capable axle. Hence why its in mustangs, GT 500, it can handle the power. As for the 4r70w is also because its very capable, but swaping it would would require the dash be pulled to put new wiring harness and ECM in.

I know that my CV's dont turn now.... Thanks for pointing out the obvious. But what i dont, is how the vacuum lockout works. Swaping out my LS might affect that. Part of the reason i asked about it on here.

In no where did i ask for your advice. But thanks for throwing it in there.

Yes i do know what will happen, I also know that i dont use 4wd unless im on slick surfaces.... So obviously there shouldnt be an issue. And with the LS it should allow for some slip anyways unlike a locker will when turning.

superrangerman2002 · #13 (**permalink**) 11-07-2009, 08:58 AM

Speaking from experince, a LS is the last thing you want in your front end.

In the first ice / snow storm you WILL stick it in the ditch. Better hope that you never have to turn while applying the throttle.

As mentioned before a selectable locker is really the only option.

That said, I don't know anyone crazy enough to drive with a locker engaged in the front on icy roads any way.

The above is all pointless anyway since you will not be stopping any better if winter weather traction is what you are after.

You will be much better off investing in a set of Severe Winter Weather rated tires for traction and stoping in the winter. BFG AT's come to mind as well as some of the other better tires out there.

steve(ill) · #14 (**permalink**) 11-07-2009, 09:01 AM

i think the factory setup on front end works pretty good Burns. I got to agree with Grennie on that one. I just dont see much of an advantage to having a LS unit in the front. Mine dont seem to slip now with the factory setup. Not sure why, but like i said, with oone front wheel off the ground, it will not spin??????

superrangerman2002 · #15 (**permalink**) 11-07-2009, 09:12 AM

I have changed and setup quite a few diffs in the past, and I do agree that the Factory LS is a great unit for every day needs of the average joe sixpack.

However, the clutch packs are the weak point, and therefore make them not nearly as robust as a gear type ls.

Would I have liked to put in a gear type LS in the rear of my '01? Absolutley, but when I can find a real low mileage LS out of a new F150 or a wrecker for $250 with ring and pinion, why would I consider anything else especially when I'm not hard core off roading my truck? 100k out of a clutch pack is not uncommon.

Burns thought is a noble one, but the physics of the situation dictate other wise.