8.8 Limited Slip Upgrade Options

[ratdude747]

Now that I'm using my Bullnose for boat dipping, one possible issue is that it's a 1WD truck. Since a 4x4 isn't in the cards (I'd have to sell the Bullnose and even then still be in the hole for anything decent), I figure upgrading the axle might be a viable option to prevent getting stuck on the ramp.

I've read of people doing this upgrade 8.8's without re-shimming if they keep the gears the same; while I have toyed with re-gearing to something in the 3.2x range, I've concluded that 3.08 is fine (and if I need more, I really just need to get a beefier truck at the point).

So, assuming that the above holds true, what's the best of these options:

1. Find a used Limited Slip carrier set and rebuild it (I've seen these on eBay on occasion for around $100-$150)
2. Buy a new carrier and swap that ($300+ IIRC)

I'd also want to do axle bearings and seals at the same time, right?

Thoughts?

[ArdWrknTrk]

I'm not one for used gears and I feel that you'd probably be even money by the time you replaced the frictions and springs, but I don't know 8.8's.
I know 9's and the bigger stuff like 10.25, D60/70/80, so I may be way off base.

Not sure why you'd need to replace any bearings or seals unless the lip has worn a groove.
In that case you'll be getting SpeediSleeve's as well.

With a new carrier you're certainly going to shimming (not so bad if you know someone with a set and you just 'swap')
I used to do that for friends with Holley jets and springs.

[mat in tn]

this is the type of thing the trac loc is for. another good option is an auburn gear unit where traction goes to the path of most resistance as opposed to least. not really cheap to do it correctly yet far less than a new truck.

[ArdWrknTrk]

I like a T-2 Torsen.  
They have them for the 8.8, but probably too much $$$ (nice in the snow, though!)

https://www.maximummotorsports.com/Torsen-Limited-Slip-Differential-C157.aspx

[mat in tn]

any type of load balancing diff should do very well here.   do NOT try a mini spool no matter how attractive the price may be. until you decide which way to go you might try the old trick of applying a "little" parking brake to crawl up the boat ramp. balancing the resistance whether by the brake drums or internally at the diff is very similar. but you do need enough grunt to overcome braking in general. just don't leave it on. get the boat up and out then release the brake.

[ratdude747]

Actually, they're about the same price as an auburn ($850-$900).  Torsens are good indeed.

New "traditional" LSDs are in the $450 range it seems. While I can get used carriers from late model mustangs (Still 8.8 31 spline) for $125 right now. Such as this one:

https://www.ebay.com/itm/285926320074

(low miles too, but being a parted out /upgraded mustang, who knows what kind of miles )

But, $160-$225 for a new set of clutches that isn't generic Chinese ($120 if you go that route on eBay)... so I dunno.

Seems the answer is "if it aint broke, don't fix it" and "buy an actual towing rig"... Is it really $400+ worth of improvement?

[mat in tn]

to me yes! but it really depends on the user and the use. I have more than one truck, so I have a couple different options.one size does not fit all!

[viven44]

I vote for a second 4x4 truck. Your truck appears to be in too nice a running shape to be sold to someone who may not appreciate its merits and pay top dollar. With Hagerty insurance and occasional boat pulling use it should be justifiable

[Nothing Special]

I've said this before, but I'm not a fan of clutch-type limited slips.  In my experience before they are tight enough to be useful they are too tight to not be annoying.  The issue I have with them too tight is cornering in snow.  They try to scuff tires (like a spool) in turns until there's enough torque to slip the clutches.  In snow there's not always enough torque so they cause a spin-out.

I know that a lot of others aren't fans of automatic lockers, so I'm not going to say that you SHOUD go that route.  But if it were me I'd put in a lunchbox locker as the low-buck option.  Their on-road manners take some adjusting to, but personally I find them pretty easy to deal with.  Certainly not invisible.  But not hard to accept.  But again, there are a lot of people who don't like them, so I'm not saying you would.

Like Jim, I'd pick a Torsen (or Truetrac, same thing, different manufacturer) as the best option for this type of use.  Pretty much completely invisible most of the time and quite effective when you need it.  And when it isn't enough the trick of a few clicks on the e.brake works GREAT with them.  This is what I have in Oswald.

If you are replacing the carrier but not the gears you at least won't have to adjust the pinion depth, and that's probably the worst part of setting up gears.  And I've heard of people not worrying about pattern, but just getting the backlash the same as it was before.  That does take shimming, but if you get the same backlash (having not moved the pinion) that means you have the ring gear in the same place as it was before, so that should mean you'd have the same pattern.  I'm not saying setting up gears is for everyone.  I've done it twice now and I get why it's worth paying a shop to do it.  But replacing the carrier without replacing the gears is about the easiest gear setup situation you'll get, so it's not a terrible place to start.

[ArdWrknTrk]

Honestly, if the standard LS diff were any good I'd say just buy an 8.8 in the right ratio complete and swap it in for the price of a couple of U-bolt's...

How much could one of these cost?
There were probably billions of 150 pick-ups and Broncos with this venerable axle 🤷‍♂️

[ratdude747]

Running shape, other than it constantly blowing up aluminum radiators,  yes.

Body wise, the cab has leaks, the exterior is "loved on", and the rear wheel arches and cab corners are rusting a bit. I'm not much of a body guy (ironic considering what the equipment I engineer produces), so I'm not super inclined to fix them now beyond what I have done. It's very much a great driver where largely any major improvement would put in a Hagerty class that would render it useless to me (to nice to drive/use).

I don't have Hagerty insurance since they seem to be more in the business of insuring "toys" than "drivers".... although lately it's only been pulling the boat (mainly due to the radiator issue).

I already have two trucks... 2nd is a loaded but very rusted 1995 Ranger (which is what I'm currently driving). Three would be something all right...

That said, I was able to get past the current hurdle, so I'm putting this thread's idea on the back burner again. Although if a 3.08 LSD did happen to fall in my lap, I'd totally do it.

To the other post: I did misremember on keeping the same gears- do need to reshim but only need to match backlash is what I should have remembered (just need to get a test indicator and mount).

[viven44]

I love Hagerty.. and they took care of me when I rear ended and totaled out a Chevy Cruze with Big Blue 2WD (the truck was unscathed except the Ford Emblem). No excuses, my inattention/fault... I called them and took responsibility it was a very easy process. I put about 2k miles/year on my trucks and cost to insure with full coverage is about ~550/year for both of them.

Not sure about local requirements of Hagerty where you live... But I don't think any of my trucks are 'Toys' by any stretch.....

They do require that one of your non-Hagerty vehicles be a 'daily driver' i.e. insured in another policy. I get away with this for the most part because my wife's car meets that criteria but they prefer to have 1 daily driver per household member.

I do question trading Big Blue 2WD from time to time for an AC cab/4x4 but it is a damn good running truck so I don't want to just give it away until I find a suitable replacement. I have a 3.06 rear end as well and I really like it over a 4.1..... just the overall driving aspects. Its just a mental feeling that I get better use of the low-end torque band on the 3.06 rear end vs 4.1. I find myself being at too high an RPM too soon on a 4.1 whereas with a 3.06, I feel like I can get more out of it at any time, if that makes sense

[Nothing Special]

ratdude747 wrote

....  To the other post: I did misremember on keeping the same gears- do need to reshim but only need to match backlash is what I should have remembered (just need to get a test indicator and mount).

In general, when you set up gears you need to shim the pinion to get the correct pinion depth and pinion preload, and you need to shim the case to get the correct backlash and total preload.  Both the pinion shims and the case shims affect pattern.

If you aren't changing gears, if you get the gears back in the same place they were you'll get the same results you had before.  Assuming the gears were properly set up the first time (usually a safe assumption if they haven't eaten themselves yet) those results will be good.

It's trivial to keep the pinion in the same place if you don't move it.

To get the ring gear in the same place at the very least I'd measure backlash and total preload before pulling the gears and then try to get as close as possible to the same readings when you put it back together.

Having said that, I don't think I did check everything before pulling the front diff out of my Bronco to put the OX locker in.  I did keep the same gears and I didn't touch the pinion.  So I did check backlash, preload and pattern as I was shimming the case.  But still, that was a much easier job than when I installed the OX and regeared the high-pinion axle that's in the Bronco now.