|
|
Thread: Limited Slip Differential (T2 LSD?)
[' This thread is 7 pages long:
1 (2)
3
4
5
6
7 '] |
admin
Administrator
Posts: 446
|
posted May 26, 2005 05:19 PM |
|
Progress...
I've made little progress since my engine has been out, and I've been traveling a lot (this has been the 1st full week I've been in town since early-April.
I've been thinking I need to see a shop manual on how to take apart a rear end, and all the parts that go into it. I'm going to check in my manuals tonight for this...
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted May 27, 2005 05:29 PM |
|
REPU:
30 spline axels
7.5" ring gear
8.75" long pinion
Do not have axel diameter measured. A friend pulled his axels out, next time I'm over there I'll measure it (timeframe...)
3rd Gen Rx7:
TORSEN LSD
30 spline axels
8.00" (203mm) ring gear
1.2085" axel shaft diameter
Supposed to fit with minimal machinework.
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge
|
|
mr-Repu
1st Gear
Posts: 17
|
|
posted May 30, 2005 02:18 AM |
|
yes im very intrested in a LSD 4 my repu aswell i thought that a s3 1st generation lsd would be sort of the same i will measure my repu splines and ill measure my friends lsd.
____________
"Bow 2 the mighty M"
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted May 31, 2005 08:26 AM |
|
1st gen is too small
Ring gear is too small. Not sturdy enough. Not designed for this much weight.
I'd like 2nd gen TII LSD meaurements to compare too.
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted June 21, 2005 01:47 PM |
|
anyone look into LSD since?
Been occupied with other things. Has the Fling PU been raced lately?
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge
|
|
admin
Administrator
Posts: 446
|
|
posted August 21, 2005 08:11 PM |
|
Has anyone seen this?
http://www.phantomgrip.com/product_lists.php?make=Mazda#
Interesting thing is all the RWD Mazda's they show are the same kit: 904-GOLD
____________
I'm The Admin, thats why!
|
|
Hunter
Hauling
Posts: 178
|
|
posted August 23, 2005 11:42 AM |
|
Courier ring and pinion in REPU differential
Does anyone know "for sure" whether 72-77 Courier ring and pinions will mount in a REPU differential ?
With or without modifications ?
Thanks,
Hunter
|
|
jfaplanet
Redlining
Posts: 356
|
|
posted August 23, 2005 02:48 PM |
|
Yes
Bruce, I have a 3.73 from a courier in my flatbed REPU. The center chunk is the same as the REPU, even the axle splines are the same. Same as the B2000 chunk you are using. I also have a 74 Courier rearend with a 4.11 rear that I may try. But yes for the record they are all the same, at least to 1984 B2000
____________
74 REPU "Red"
74 REPU "Jethro" "TII"
74 RE-Courier vert
79 SA-SE(aka deathtrap)
79 SA-SE-FC (project
turbo)
http://home.bellsouth.net
/p/PWP-crgj
TN Forum:
http://tnrotary.10.forume
r.com/
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted September 22, 2005 10:03 AM |
|
3RD GEN LSD compatability confirmed
Hi,
I have talked to someone who has put a 3rd gen TORSEN in his turbo REPU, 460rwhp @ 14psi and it has not broken the diff. Confirmed it can fit; axel diameter and spline count the same.
There is a spacer that needs to be fabbed and added, longer grade 8+ diff to ring gear bolts that also need their heads machined down for clearance and tack welded on the threaded end on so they won't back out. Only bummer is the torsen is $700+ used and hard to find.
I have also found this website, seeing that 3rd gen is 8" 30 spline, the one listed for RX7 WITH TURBO 8.0" may work.
http://www.reiderracing.com/pgpowerbrute.htm
Also toyota tacoma truck diffs have same ring gear diameter and spline count............
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge
|
|
klaus42
Rotorhead
Posts: 1877
|
posted September 22, 2005 10:16 AM |
|
Nice!
Now, is that Toyota one a limited slip...?
|
|
admin
Administrator
Posts: 446
|
|
posted September 22, 2005 10:46 AM |
|
Spacer?
What is this spacer?
Where does it go?
Can they guy you talked with make a few complete units of them for us?
Also, does anyone have a complete diagram of the Rear end? Maybe someone can scan something in from the workshop manual? I'm still not clear on all the parts and peices that go into the rear pumpkin... and how they can be swapped out... And I don't really want to drop my rear end, open it up to find out.
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted September 22, 2005 11:03 AM |
|
spacer between diff and ring gear
and yes klaus, all the diffs on that website above are lsd. he may be able to do some for us, he is busy of course but i'll ask if he's interested. brad.
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted September 23, 2005 10:58 AM |
|
quote:
Yeah, its a common six bolt pattern, but my particular problem (which most ppl probably don't share) is in finding a decent LSD/disc brake rear end that require little modification to swap under my truck.
Welding on suspension mounting tabs is managable. Narrowing a rear end qualifies as PITA.
A late model blazer/s10 rear end is probably going to be what I go with. Especially since I can pick them up for $150.
Even with the modifications quite a bit cheaper/easier than the recent Torsen solution posted.
It's all abount time vs money compromise like u talked about in the other post rotormonkey.
Finding a rear with the diff flange in the exact same spot is very important so the driveshaft won't be cock-eyed, eat u-joints, premature wear the center bearing, and vibrate the whole truck. I have not heard of one that meets these specs. The isuzu truck one had it's pumpkin off to the side.
It'll be impossible to find a 4.625 like what REPU has. Those gears help make the truck in my opinion.
Cutting and welding leaf spring plates on another axel tube needs to be done right so pinion angle and spring placement is correct. Not impossible by any means!
No truck or SUV will have a Torsen diff, those things are state of the art.
Front brakes do 80% of the braking so rear drums ain't no biggie, they're only doing 20% and repu drums are big. Rear discs weigh less and cool better but I only need that when towing.
I have seen Torsen's go for $350 from guys putting LS1 or some other pissed on monstrosity into their 3rd gen. And have some contacts for good used parts deals.
Brad
|
|
rotormunky
Redlining
Orlando, Florida
Posts: 424
|
|
posted September 24, 2005 11:23 AM |
|
quote:
Finding a rear with the diff flange in the exact same spot is very important so the driveshaft won't be cock-eyed, eat u-joints, premature wear the center bearing, and vibrate the whole truck. I have not heard of one that meets these specs. The isuzu truck one had it's pumpkin off to the side.
I eyeballed (dunno why I didn't put the tape on it) the S10 rear and I'm 95% sure its centered. If its off, its not by more than an inch I'm sure.
quote:
It'll be impossible to find a 4.625 like what REPU has. Those gears help make the truck in my opinion.
Well, I'm probably gonna stick to the ~3.80s that came w/ my '77 but I might go as high as ~4.11s since I'll be keeping the five speed. Either its as simple as picking up a Jeggs/Summitt catalog. I think a 4.10 runs about $250, a 3.73 is under $200. THe stock 3.42 would be livable but there are lots of options for a chevy rear end and they're all easy to find and relatively inexpensive.
quote:
Front brakes do 80% of the braking so rear drums ain't no biggie, they're only doing 20% and repu drums are big. Rear discs weigh less and cool better but I only need that when towing.
Oh man, I've got some sort of deep-seated thing about drum brakes. I can't believe they're used. Its like some kind of Rube Goldbeg machine in there! :)
I mean, spings, clips, springs for clips, clips for your springs, springs for your springs . . . bleh. If you don't constantly adjust them they stop working within 10k miles. I've seen people get 100K miles on a set of shoes cause they never adjust them. If you can believe it GM doesn't even punch out the adjustment holes on teh backplates from the factory.
I hope to be hauling a motorcycle trailer quite often so that's one reason, but to be honest with you, my main concern is maintenance. Its worth it to me to not have to mess with drums. I can swap pads on disc brakes in 15 minutes.
I figure if I carefully measure the the angles, welding on the perches isn't a problem. Figure even with the cost of brake fluid, new pads, a 4.56 ring gear and synthetic gear oil I can still come in WAY under $500. And I know that the rear end will stand up to 300+ ftlbs without coming apart on me. If I can find a better all-around solution than that I'll jump on it, but for right now its the best solution I've got.
Its just a personal preference, I wouldn't necessarily say it SHOULD be done by anyone, but its sure something I'm looking forward to.
____________
-Martin
Orlando, Florida
http://www.themonkeyhouse.org/REPU
'77 REPU (Some assembly required :)
'91 Cabrio (Battered and bruised, but she's still my baby.)
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted September 24, 2005 11:58 AM |
|
cool martin, hope it works out
I just found a torsen for $250.
If diff is even 1" off then ujoints will wear much quicker and can vibrate. If it's 1" to the drivers side then gastank is in the way.
Sounds like a neato project, I hate drums too, *royal bitch* to get off, but just put *all* new drums and hardware on there including Porterfield R4S shoes. Rear shoes in my Amigo are stock, don't squeal, after 126,000 miles and I have towed the racecar about 22 weekdnds with it. Keep us updated. What year S-10 rear, we need to know the bolt pattern so I can ask the brake guy if he will make front hubs for big brakes. Brad
|
|
rotormunky
Redlining
Orlando, Florida
Posts: 424
|
|
posted September 24, 2005 12:58 PM |
|
quote:
I just found a torsen for $250.
If diff is even 1" off then ujoints will wear much quicker and can vibrate. If it's 1" to the drivers side then gastank is in the way.
I hate to say anything without actually having info but what I meant to say was that if it was even an inch off I would have likely noticed. I'm 95% certain its centered. So that part shouldn't be a problem.
quote:
Sounds like a neato project, I hate drums too, *royal bitch* to get off, but just put *all* new drums and hardware on there including Porterfield R4S shoes. Rear shoes in my Amigo are stock, don't squeal, after 126,000 miles and I have towed the racecar about 22 weekdnds with
See that's what bothers me about them. If I'm getting 100k miles out of a set, they aren't really doing anything. Which puts 90% or better front bias on the truck. W/ discs, I know what I'm getting, and with a $25 adjustable proportioning valve, I can control it. I'm just more comfortable w/ the discs.
quote:
Keep us updated. What year S-10 rear, we need to know the bolt pattern so I can ask the brake guy if he will make front hubs for big brakes. Brad
Like I said, should be 5 X 4 3/4". Standard five bolt chevy pattern.
Charles seems to have cooked up an alternative that lets you keep the six lug and get lsd, but I still don't know if its a better alternative to a chevy conversion just yet.
Frankly I'm not crazy about the durability of a b2000 rear end. I could be (gladly) wrong on the subject, but I haven't heard of too many people rnning 200-300 hp through the rear ends.
____________
-Martin
Orlando, Florida
http://www.themonkeyhouse.org/REPU
'77 REPU (Some assembly required :)
'91 Cabrio (Battered and bruised, but she's still my baby.)
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted September 25, 2005 09:46 PM |
|
I'm quoting Charles's post over here on the LSD thread so mabye we can keep the brake thread about brakes.
quote:
Martin, The axles from the B2000 is what you need. I am going to try to get my hands on a B2000 rearend. Then all I need is the center chunk out of the GSL-SE or and 84-85 GSL with limited slip. From the research I have done it appears the these 2 combinations of parts will mate up and and give us a limited slip rear that will fit in the REPU with only minimal welding on the rear so that the springs pirches will be in the correct place. I will let you know more when I get all the parts and see if it will bolt up. Charles.
The Nashville Pull-a-part has B2000 rearends for around $40, now I just have to find a limited slip from a RX7.. later.
Here is some info. 84-88 N/A Rx7 LSD all uses a 7" ring gear, large axles = 27mm axel diameter x 26 splines.
Now, just thinking out loud here, if I can get a LSD from a 3rd gen which uses a 8" ring gear, and 30mm diameter axels, would not going to a smaller 7" ring gear and smaller 27mm axels create two points of failure?
|
|
Brad
Rotorhead
Posts: 1672
|
|
posted September 26, 2005 10:29 PM |
|
I'm working on a group deal buy
For the TORSEN LSD installation and going over some details. I'll let you know. End user may need to setup rear axel end play by measuring with dial indicator and using shims to get proper end play. Unless you want to freight ship your entire 3rd member minus brake hardware.
!!!!The *fun* of custom work!!!!
Stay tuned.........
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge
|
|
JackAmmann
Newbie
Posts: 4
|
|
posted October 08, 2005 06:13 PM |
|
quote:
I had an interesting conversation with the guy who runs Checkpoint Engineering (they have changed their name) and he says the rear diff of the REPU can be swapped out for one out of a Turbo2 RX-7.
Can anyone explain (or point to a website) how the differential is constructed in the REPU: as in:
What are all the different parts?
What can/may be swapped out?
How do you change ratios?
The people at Racing Beat can give you any information you want about REPU differentials. If I remember correctly, the differential of a REPU is larger than an RX7. And the way one changes ratios in a REPU is to install a different ring and pinion.
____________
Jack Ammann
Greetings from The Lone Star State.
Home of the San Antonio Spurs...the 2005 NBA World Champions.
|
|
FLIBOYZ6
Revvin Up
great
Posts: 72
|
|
posted October 13, 2005 01:53 AM |
|
TO CHANGE THE RATIOS IN THE REAR THE HOLE THIRD MEMBER CAN BE CHANGED FORM THE COURIER BUT NOT THE HOLE AXLE
AUTOS HAD 4.3-1
4 SPEEDS HAD 4.11-1
|
|
| All times are PST (US)
[' This thread is 7 pages long:
1 (2)
3
4
5
6
7 '] |
|
|
Edited By: 
