CJ (FS)
CJ (FS) GRM+ Memberand HalfDork
4/7/21 9:21 p.m.

So I have a very long-term 1973 Volvo 1800ES wagon.  At some point, I am thinking it might need a LSD in it's Dana 30 differential.  Apparently, there were cars that came with the LSD, but they were a dealer installed option, like AC in these cars.  The actual Volvo LSD units are quite rare.

I have read that there are Dana 30 LSD Jeep differentials, although I have no idea of what years they might come in or what else I need to know.  My ES started life as an automatic, but I will be installing a 4-speed with overdrive.  The rear end ratio I need to end up with is 4.33:1 - currently, it is a 4.10:1.

The other option I ran across is a Wavetrac Differential.  Never have heard anything about these but thought someone might know something.

Lee
Lee UberDork
4/7/21 10:05 p.m.

Only Jeeps with a factory LSD in a Dana 30 were WJ Grand Cherokees with Quadra Drive Vari-lok.

I'm no WJ Quadra Drive expert, but I think that the D30 in the front of the WJ has a unique pumpkin machined to fit the Vari-lok pump assembly, so chance of it fitting in the Volvo's rear diff without modification are at best plausible.

There are a ton of aftermarket D30 LSD options though.  I've got a D30 Truetrac (torsen style) for my XJ.  There are a ton of lockers too.  A lot of folks poo, poo, on street driven ratcheting lockers, but the clicking around corners isn't that bad.  I've got a Lock Right in the D35 and an Aussie Locker in the D30 of my Wrangler, both drop-in "lunch box" lockers.

 

Streetwiseguy
Streetwiseguy MegaDork
4/8/21 12:12 a.m.

I have worked on Volvo cars since 1982, and I have never, not once, ever, seen a factory Volvo lsd that wasn't broken.  Period.  The aftermarket stuff fits quite nicely.

CJ (FS)
CJ (FS) GRM+ Memberand HalfDork
4/8/21 3:17 a.m.

In reply to Streetwiseguy :

So did the Volvo dealers just install the Dana LSD in the rear end and berkeley it up or what?  That just seems bizarre.

Which of the aftermarket LSDs do you like?

Streetwiseguy
Streetwiseguy MegaDork
4/8/21 6:44 a.m.

Volvo thought they were making it stronger by going to four spider gears, but instead they were filling the case with fragile pins.

I forget the exact unit, but I installed one in a 347 Ford powered one a few years back, and it has survived.

I think it's pretty common knowledge on the Volvo boards, but I can find out if you want.

gearheadmb
gearheadmb SuperDork
4/8/21 7:23 a.m.
CJ (FS) said:

I have read that there are Dana 30 LSD Jeep differentials, although I have no idea of what years they might come in or what else I need to know.  My ES started life as an automatic, but I will be installing a 4-speed with overdrive.  The rear end ratio I need to end up with is 4.33:1 - currently, it is a 4.10:1.

I dont know of any factory jeep limited slips that would fit your need, but they did use the d30 in front of yj and TJ jeeps, so the aftermarket will have whatever you want. 

I've had lockrite lockers in a few offroad vehicles and I wouldn't want one in a street or race car. The clicking didn't bother me, it was the diff being locked when I didn't want it to be causing it to push. 

captdownshift (Forum Supporter)
captdownshift (Forum Supporter) GRM+ Memberand UltimaDork
4/8/21 7:28 a.m.

Diffwizard has cost effective aftermarket option, no paddle needed. 

Fueled by Caffeine
Fueled by Caffeine MegaDork
4/8/21 8:05 a.m.

As lee mentioned the Detroit true trac lsd is available and should do what you need until the power goes big time. 
 

https://www.summitracing.com/parts/dtl-912a585

Lee
Lee UberDork
4/8/21 12:51 p.m.

The Gov Lock has a bad reputation in just about every pre-'90s vehicle it was used in.  The later ones aren't great, but the early Gov Lock has the nickname Gov Bomb for a reason.

The front axle of the base model of most solid axle (and some IFS) Jeeps from 1972-2018 was a Dana 30.  Like I mentioned above there are a ton of options.  XJs had high pinion Dana 30s for most of their run, but the carrier is pinon agnostic, you can put the carrier from an HP D30 in a LP D30 and vice versa.  JK D30s are HP too and use a different bolt size for the ring gears.  There are 2x carriers depending on gearing, they split between 3.54 and numerically lower gears and 3.73 and numerically higher gears.

For your 4.33 gears, you'll want a LSD for a D30 that's 3.73 and numerically higher (lower geared).

There are tons of places to buy aftermarket Jeep parts.  I seem to say tons a lot.

4wheel Parts

Quadratec

East Coast Gear Supply

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