LSD Upgrade for 16V + W124! - Page 2 - PeachParts Mercedes-Benz Forum

gsxr · #1 01-17-2009, 05:45 PM

Quote:

Originally Posted by Turbo E320

You don't need a real LSD to make a springblock work. Phantomgrip.com will make a spring block for 500 for anyone and they are designed to turn open differential into an LSD. They have 3 grades of springs. Their heaviest lock up to 75% in light japanese cars like 240sx's(2600lbs) and as low has 40% in big heavy cars like a sl500(4000lbs).

All it does is push the the spider gears apart to prevent the open diff action.

Phantom Grip is still not a real LSD. And it's not cheap. For vehicles where there is no LSD option available a reasonable cost, yeah, it might be worth trying it out for $300-$500 (plus lots of labor to pull the diff apart, install it, etc). However for most Mercedes (including the 123, 124, 126, 201, 202, and many 129/140 chassis) there is a "real" LSD option available for $750-$1000 (cost varies depending on the exact year, model, and gear ratio). If you need it bad enough to afford an PG, keep saving your pennies until you can get the real deal. You may want to do some Google searching for PG failures... when they fail, it usually ain't pretty. MB clutch-type LSD's rarely fail, they just wear the clutches, and those are replaceable.

Johnref, there are factory LSD options for your 126. That's the way to go. A spring block (as shown in the first post on this thread) adds extra lockup for race purposes, but isn't really needed for street use. The spring block is far more effective when used in an LSD than in an open diff.

Johnhef · #2 01-18-2009, 08:35 AM

The car is rarely driven other then to track events or the shop. It currently has a 3.07LSD in it.

gsxr · #3 01-18-2009, 10:50 AM

Quote:

Originally Posted by Johnhef

The car is rarely driven other then to track events or the shop. It currently has a 3.07 LSD in it.

Ooooo, nice. You could have someone fabricate a spring block to work with your 126 (210mm) LSD carrier, it would just be a little larger than the one shown in the original post for the 185mm carrier. But you still need to remove the C-clips which lock the axle flanges into the diff - probably not a concern on a track car, though. Have you ever replaced the clutches in your LSD? If they're original, I guarantee they're overdue for a refresh... a new clutch pack might provide the improvement you're looking for, even without the spring block.

Johnhef · #4 01-18-2009, 07:59 PM

Well, its freshly installed about 2 weeks ago (see http://www.peachparts.com/shopforum/showthread.php?t=242313), I'm curious as to how much lockup its going to provide, auto-x season starts in April so I'll get my first chance then to try it out. The clutches in the 2.24 LSD the car originally had were worn out (tons of play with the flanges) and instead of replacing them, I opted for a different LSD gearset.

I love how the car accelerates with this one in it now. I only need one of two things now.

A) different gearing for 4th gear
B) different trans with more gears

gsxr · #5 01-18-2009, 09:36 PM

A) UH, well, your option there would be to drop back to a 2.86 or 2.65 ratio, lol.

B) I know a guy who can install a 5-speed 722.6 into your car, and program a standalone controller, but it will be about $5-6k out the door (I believe that includes labor, installation, tuning, and a used 722.6 tranny). In that trans, 4th gear is 1:1, and fifth is an 0.82 overdrive (I think). It's the perfect tranny - except for the cost.

C) I'm willing to bet that you find the clutches are worn out on the donor 3.07 diff, but you won't know for sure until you try it out. For autox use, you may need a custom spring block as shown in the first post on this thread. The factory LSD is better for street use than for race use, IMO...

Roncallo · #6 01-18-2009, 11:24 PM

Quote:

Originally Posted by gsxr

A) UH, well, your option there would be to drop back to a 2.86 or 2.65 ratio, lol.

B) I know a guy who can install a 5-speed 722.6 into your car, and program a standalone controller, but it will be about $5-6k out the door (I believe that includes labor, installation, tuning, and a used 722.6 tranny). In that trans, 4th gear is 1:1, and fifth is an 0.82 overdrive (I think). It's the perfect tranny - except for the cost.

C) I'm willing to bet that you find the clutches are worn out on the donor 3.07 diff, but you won't know for sure until you try it out. For autox use, you may need a custom spring block as shown in the first post on this thread. The factory LSD is better for street use than for race use, IMO...

The 722.6 is a perfect tranny for the older cars. It has as you say over drive plus a user selectable 1'st gear start (W/S) modes and a lockup converter. It would allow the use of a 3.07 rear with highway cruising RPM of a 2.47 rear. It really would be a nice upgrade. One of the first things I would like to do is start to experiment with the PCS controller after I get my current 722.6 running. I think it could be done for about $2500 to $3000 in parts including a used trans, controller, shifter, wire harness. I believe you could use your old drive shaft.

Johnhef · #7 01-19-2009, 07:09 AM

haha thanks, I will definitly keep that in mind. I'm sure I can get a 722.6 for nothing or next to nothing if I keep my eyes open. The clutches on the 3.07 sem to be in pretty good shape still, the donor vehicle had about 80k on it, and all I can tell so far is that this one actually works over my old one, but yes the first ax will show how well it works. I've got a drag event and a day at summit point before the first ax though.

gsxr · #8 01-19-2009, 10:36 AM

It should do fine at the dragstrip, not sure about a road course, and autox is probably the most difficult test. What were your dragstrip numberrs with the 2.24 gears, btw (esp. the 60' time)? It will be interesting to compare with the 3.07 gears!

Johnhef · #9 01-19-2009, 08:21 PM

At the last minute, I decided to leave the car at home last November when I last went to the dragstrip, and I regretted it.
Best 0-60 prior to the swap was 8.0 seconds, thats the only measurement I took.

Dan16V · #10 08-09-2010, 01:38 PM

Hi guys,
I have a few more sets of these LSD spring block kits available again!

It fits the 185mm diffs found on the 16V and W124s. It fits both regular LSD and ASD diffs. (Note: ASD must be disabled if the spring blocks are installed.)
The kit is available with both standard and heavy duty springs depending on how much lock up you're looking for.

See this writeup at 190Rev for an example of an installation.

The pricing info again is $200 for the kit + $10 for US shipping. Extra set of springs is $25. If you're international, PM me with your address for a shipping quote. Most of the time it's around $25.

PM me if you're interested.