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TrueTrac limited slip selection/install -- HELP!!!!

A

Anonymous

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Seems like the more I get into this, the more confusing it gets. I ordered a TrueTrac limited slip from Reider Racing for my car several months ago. I'm about ready to install (or to help a knowledgable friend install) so I've begun asking questions and I've managed to confuse myself all over again. Thanks to all of you that responded to my previous post. My car is an 82 242 w/5.0L conversion. Originally it had a 3.54 gear; however, the previous owner swapped in a rear end out of an 84 turbo wagon to get the 3.73 gear. There doesn't seem to be any surefire way of distinguishing the 1030 rear from the 1031 short of pulling the diff and measuring the ring gear diameter - 1030 has 7.25", 1031 has 7.75". I guess the 1030 is a Dana30, while the folks at Reider Racing refer to the 1031 as a 'corporate Volvo axle'. The folks at Reider racing know the TrueTrac will work with the smaller ring gear, they have no idea if it will work with the larger ring gear. Apparently the pinion gear is a different length and diameter in the 1031 as well.

So, anyway of telling which rearend - 1031 or 1030 - came in the 84 turbo wagon? Anyone know for sure whether the TrueTrac will work in either or both rear ends? A few folks have told me they think the TrueTrac will work with either size ring gear (this would mean that the inner ring gear diameter and bolt pattern are identical between the larger and smaller gears), but that the pinion bearings and races are a different size than the standard Dana30/1030 pinion components, and must be sourced from Timken or Volvo. Any help unravelling this mystery is appreciated as I've already bought the unit, and am trying to figure out if it's going to work, without pulling my stock one apart. Thanks - M
 
At one point I was quite sure that all turbos had 1031's but nowdays I'm never sure of myself ;)

I would be surprised to find a turbo w/o a 1031.
 
Occurs to me another question to ask is whether anyone has a turbo 240 series that they installed a TrueTrac in? If so, any challenges or difficulties you recall with the install?
 
Actually Doug, it was after speaking to Patrick last night by phone that I started this journey. He tried to put a TrueTrac in a 1031 and ended up buying a smaller 1030 and putting it in that. He seemed to think it would go in the 1031, but a number of the bearings and seals required are different than the Dana 30, and he had access to the Dana 30 stuff. So, been there, done that, and he confirmed that I am in fact confused.
 
IIRC, the 240 turbos only had a 1031 housing if it was a manual trannie......that was the way it was until 1985; then all the 240 turbos had 1031 housings; whether auto or manual trans......

the easy way I have found to id which is which is look at them.....a 1031 housing is bigger and has larger gussets....if you had a 1030 and a 1031 sitting side by side, it would be very obvious.....(yeah, easy for me to say)....

as far as 1981 240s, I am not sure if the 1031-only-with-manual-trans rule was in effect; but I am sure of it for 83-85 240s......and like I already said, in 1985, all 240 turbos got the 1031 housing.....

the turbo manuals had 3.73:1 ratios; turbo autos had 3.91:1 ratios......

have you talked to MVP about your posi? they should have an answer to your dilemma.....HTH
 
Talked to Seth at MVP and Bernie at Reider Racing. Reider confirms only that the TrueTrac I bought will fit in a Dana 30 rear end. No one, self included, seems to know for sure which Volvos had the Dana 30 (1030) and which ones had the 1031. Seth seemed to think the TrueTrac would work with either provided you go straight to Timken or Volvo for different pinion bearings/races than those that come with the Dana30 rebuild kit. However, Reider has drawings that indicate that the pinion gear is longer, the shaft is bigger, and the ring gear is bigger - leading them to conclude that the TrueTrac diff won't go in a 1031 rear end. Appreciate you guys trying to help me out - maybe we can keep this one near the top of the list and see if anyone out there actually knows. Compounding this is my own ignorance - I don't know for sure what car the rearend in mine came out of. My brother had it at the time, and had a turbo 240 wagon sitting around for parts. He pulled the rear out of the wagon and put it in the 242 to take advantage of the 3.73 gear. But none of us knows for sure what year the wagon was. Or what kind of tranny it had in it. I only know it was a non-intercooled 240 turbo wagon. Any other ideas/thoughts? Stealthfti - don't know if you have a 1030 and 1031 sitting there side by side - if you do, is there any chance you could take some measurement - say from the rear cover flange to the front most part of the pinion housing on each and let me compare those to what's in my car? Just a thought. Thanks for your patience guys - Michael
 
no, not side by side, but I will see what I can do....but it might be sunday before I can get the info you need.... :x:
 
Stealthfti- I'm grateful for any additional info you can obtain - whenever! It's obvious to me I'm not going to be diassembling anything until I can try to figure out what's going on. Thanks - Michael
 
Culled from Dave Barton's page for what it is worth:

"UPDATE NOTE: (04-08-02) Derek Walker wrote that while in the process of examining different options for an LSD for his '89 745 GLE with a 5.0L Ford engine and 4.10:1 differential, he checked with Reider Racing regarding the TrueTrac per the recommendation here. Reider responded that his 1031 Volvo housing will NOT accept the TrueTrac LSD due to slight dimensional differences from the 1030. They've got a few returns from Volvo owners due to incompatibility issues. It's not clear if the issues are unique with the TrueTrac LSD or the 1031 housings. "

JB
KTP
 
Yeah I read that quote from Dave Barton, too. Not to dis Dave in any way at all, but that seemed to be all "3rd hand versions of guesses", not really very useful, except to warn a neophyte that he was taking a risk.

I am sure that a true trac will fit my 140, as long as I go with a 3.73, which I plan to do anyway. So, ...I can sit back as a spectator here :D. I just have to get to get into a position where the money isn't crying to be spent on other more practical aspects.

If anyone in Canada wants a Truetrac and is willing to pay at least part upfront, they are available on about 6 weeks notice @ ~$460CDN+tax to your door. Pretty competitive with Reider once you allow for duties and so on. Drop me a line: iadr@hotmail
 
Well - interesting; Reider was VERY clear with me -- they didn't have a clue if it would work in the 1031 or not. I guess I thought that all the 7 series turbo cars had 1031's in them, and my memory tells me I've read threads/posts about 7 series cars with the TrueTrac. Hopefully someone else will read this saga and let me know if it will or won't work. I don't think I'm gonna be willing to pull mine completely apart to find out.
 
I have two cars that would presumably be a Dana1030 rear ends, one in my GL the other in my GT. I have a new to me 242Ti, which, would guess have a 1031. All in the same driveway

Tommorow I'll measure differances.... and get back to you guys

Jordan
 
Well, a bit more info - I just spoke with another V-8 bricker who has the same rearend in his that I do in mine - out of an 84 turbo model. He said the PowrLok rearend for the Dana30 went right in - a very straightforward swap by a Jeep/4x4 shop. Took about an hour and half, no alternate bearings or races, etc. Just had to be measured and re-shimmed - of course when you change bearings and diffs dimensions will probably change. So I'll talk to Reider Monday and find out if the TrueTrac and the PowrLok for the Dana30 are the same dimensionally. Thanks guys - M
 
I have a true trac in my 260 which has the Nissan 3 litre V6 turbo in it. I have had it installed for 3 years and haven't had any problems with it except for things that I have caused. The centre itself is very strong but as a hint, with a heap of power and torque, don't dump it in reverse accidently or on purpose. I managed to put a 10 thou bend in the pinion. I have also snapped an axle but I think the guy put the axles in the wrong side when it was rebuilt. When I ordered my centre there were two choices, one being up to 3.73 ratio and the other was from 3.73 up. Because it was for a jeep, not everything went to plan, it fitted in there fine but we had to make sleeves to go over the bolts that bolt the crown wheel to the true trac. As with any change in the diff, you need to set up the correct backlash and I suggest also purchasing a new collapsable spacer. Apart from that, a full set of new bearings and we were away. I have no idea of the difference of a 1030 and 1031 but I have seen many early diffs and late diffs in pieces and can offer you this information. If the crownwheel sizes are different between the 1030 and 1031, then I have a 1031 in my car. I have destroyed many diffs from taking half of the teeth off the pinion to destroying spider gears. I have seen the smaller and larger crown wheels and pinions and they are in different housings. The larger crown wheel and pinion in the 240 in Australia looks like a 740 diff. The 740 runs a different set up of the upper trailing arms which bolt to the right hand side of the diff centre as you stand at the back of the car looking at the diff. If there are the extra castings on the housing with threaded holes, then that is the larger of the crown and pinions.

Regards,

Michael

1981 264 GLE, 3 Litre Nissan, quad cam, 24 Valve, V6 turbo, 5 speed Manual, true trac diff, 225 rear horsepower
 
here is what I found:

a 1030 is about 10.125 inches from the rear cover surface to the front of the pinion neck......that's ten and an eighth inches to graduates of american public schools...

a 1031 is almost exactly .5 inches longer.....that's a half inch longer......

visual differences:

a 1030 has a single gusset on each side of the pinion neck, roughly centered along the pinion centerline...

a 1031 has 2 gussets on each side; with the larger gusset spreading back from the top of the pinion neck; and the smaller gusset following the pinion centerline...

what the longer neck actually means as far as fit goes, have no idea.....what needs to be done is some research in the parts microfiche to compare internal components....

why? because just because the neck is longer, that might only affect the pinion shaft, not the carrier....someone already alluded to the fact that for different ratios in a dana rearend, there are different carriers.....this is not because the ring gear is a different diameter for the different ratios.......it is because the ring gears are of different thicknesses: to accomodate the differing number of teeth on the pinion as well as on the ring gear itself......

what I am saying, in a roundabout way, is that all you might need is a ring gear spacer--a shim ring--in order to space the ring gear against the pinion when you install your posi carrier.....

you need to spend some time going through the parts 'fiche....it will probably take a couple of hours to wade through and compare the part numbers.....been there, done that on other projects....
 
I just crawled out from under the bottom of the car myself. So, your measurements match up with mine perfectly. I measured 10.625" from rear cover flange surface to tip of the pinion casting. Mine also has the 2 gussets on each side rather than 1 - and I believe this is the easy way for all of us to know whether we've got 1030's or 1031's. The extra 1/2" of pinion casing length matches up with what Reider told me - they indicated the pinion gear in the larger rear end was 1/2" longer in the bigger rear end than in the Dana 30. I guess I'll find out when I take it apart, but supposedly the ring gear outside diameter is 1/2" bigger than the Dana30/1030 - 7.75" vs. 7.25". I believe the inside diameter and bolt pattern however is the same on both gears which is what allows for the same diff to work with both gear sets. I also got a bunch of numbers off my tag, the rear end housing and the ring gear. I'll hit the fiche with these and also get Reider to help me decipher. Did you notice any numbers/letters on the housing - as you're facing the back of it, they'd be at about 1 o'clock? Mine has "DA 10" -- I wonder if the 1030 says something different there? Thanks for the help!!!!
 
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