Results 1 to 17 of 17

LENGTHEN a rear end??

This is a discussion on LENGTHEN a rear end?? within the Drivetrain forums, part of the LSx Technical Help Section category; Ok, i found an old rear end from a (1980? i think) trans am with rear disk brakes. I am ...

  1. #1
    Junior Member nativetalon's Avatar
    Join Date
    Dec 2007
    Location
    pembroke, nc
    Age
    34
    Posts
    59

    silver & black
    2000 TA 1979 TA

    LENGTHEN a rear end??

    Ok, i found an old rear end from a (1980? i think) trans am with rear disk brakes. I am hoping to fab it to fit on a 2000 ws6 T/A (7.5). The rear end out of the 80 model is 4 inches shorter than the rear in the 2000 model. The hoghead is 1" wider (shaft to shaft) and 2" thicker than the 7.5. I have heard of narrowing a rear but not lenghtening. Is this practical? Or will it work. If so, wat needs to be done? The rear end was free, so hoped it was worth a try. Thanks.

  2. #2
    Super Moderator
    pajeff02's Avatar
    Join Date
    Feb 2009
    Location
    Mansfield, PA
    Posts
    21,576

    Black & Blue
    '02 WS.6 / '07 Suburban

    You could certainly extend the axle tubes and purchase longer axles. You would need a jig to ensire that everything stays in alignment or you would end up breaking parts and tearing up tires. If you wanted to be real dangerous, you could use the existing setup with longer wheel studs and spacers. Another option is a change in wheel backspacing if it would otherwise clear the inner wheelhouse. In the long run though it sounds like one big headache.

  3. #3
    Junior Member nativetalon's Avatar
    Join Date
    Dec 2007
    Location
    pembroke, nc
    Age
    34
    Posts
    59

    silver & black
    2000 TA 1979 TA

    I think i can extend the axel tubes and they will be straight. But will it still be strong. Or will that create a weak point. Also with new performance ring, pinion, and axels will it be strong enough to hold around 650 to 700 HP?

  4. #4
    Super Moderator
    pajeff02's Avatar
    Join Date
    Feb 2009
    Location
    Mansfield, PA
    Posts
    21,576

    Black & Blue
    '02 WS.6 / '07 Suburban

    At that power level, you need either a Dana, a 9" or Fab 9 imo.

  5. #5
    NASCAR Go Fast, Turn Left ntimid8r's Avatar
    Join Date
    Aug 2001
    Location
    San Diego, CA
    Posts
    8,048

    383 w/Meth & ProCharger
    2001 Camaro Z28

    I don't think this is a practical thing to do. Why do you want to change out your existing rearend anyways???? The old adage comes to play here, "If it ain't broke, don't mess with it".

    Quite frankly, in this scenario you're spending more money and time than necessary on a 7.5 rearend. Yes you can make a second gen rear meet the fitment specs for a 4th gen but why??? The 7.5 is not a "strong" rearend to begin with. I'm sure you can find a used, stock 4th gen rear on craigslist or wherever for a couple hundred bucks. Which would be cheaper overall than buying new axles, bearings plus fab work on the 80's housing.

    Another cheaper alternative to get a stronger rear and not shell out a couple grand for a new, bigger and better one....is to locate a ford 8.8 rear. It can be modified to fit an fbody. I don't recall all the specs for doing that, I'd have to research the details but I've read of a few that have done it. An 8.8 is slightly stronger than our stock 7.5.

  6. #6
    NASCAR Go Fast, Turn Left ntimid8r's Avatar
    Join Date
    Aug 2001
    Location
    San Diego, CA
    Posts
    8,048

    383 w/Meth & ProCharger
    2001 Camaro Z28

    Quote Originally Posted by pajeff02 View Post
    At that power level, you need either a Dana, a 9" or Fab 9 imo.

  7. #7
    Junior Member nativetalon's Avatar
    Join Date
    Dec 2007
    Location
    pembroke, nc
    Age
    34
    Posts
    59

    silver & black
    2000 TA 1979 TA

    How much HP will this setup hold at the rear tires?

  8. #8
    NASCAR Go Fast, Turn Left ntimid8r's Avatar
    Join Date
    Aug 2001
    Location
    San Diego, CA
    Posts
    8,048

    383 w/Meth & ProCharger
    2001 Camaro Z28

    Quote Originally Posted by nativetalon View Post
    How much HP will this setup hold at the rear tires?
    Every rearend varies due to mileage, gears and if it's with a manual or auto. But to throw out a number I'd say 400 tops!! But be ready to get a stronger rear in not too long.

  9. #9
    Junior Member nativetalon's Avatar
    Join Date
    Dec 2007
    Location
    pembroke, nc
    Age
    34
    Posts
    59

    silver & black
    2000 TA 1979 TA

    The rear end from the 80 model looks so much bigger than a 7.5That's y i was hoping it was an 8.8. Or something like that. Figured since i already had it. And it was pontiac. That it would be a close mod and stronger. Especially with upgraded Axels and gears.

  10. #10
    Junior Member nativetalon's Avatar
    Join Date
    Dec 2007
    Location
    pembroke, nc
    Age
    34
    Posts
    59

    silver & black
    2000 TA 1979 TA

    Hey, I measured both rear ends again today. The "bandit" style T/A has a definately larger hoghead and 3" tubes. Compared to 2.5 inch tubes on the 2000 T/A. What kind of rear end is it?

  11. #11
    Moderator Cutlass's Avatar
    Join Date
    Apr 2008
    Location
    Madison, WI
    Posts
    6,998

    1999 Formula WS6 M6-sold
    2001 Silverado Z71

    8.5" 10 bolt. Its the axle our cars SHOULD have came with. Its not the strongest thing in the world but Grand National guys are taking these rears into the 11s and 10s.

  12. #12
    Junior Member nativetalon's Avatar
    Join Date
    Dec 2007
    Location
    pembroke, nc
    Age
    34
    Posts
    59

    silver & black
    2000 TA 1979 TA

    Quote Originally Posted by Cutlass View Post
    8.5" 10 bolt. Its the axle our cars SHOULD have came with. Its not the strongest thing in the world but Grand National guys are taking these rears into the 11s and 10s.
    Thanks. But how much will i have tied up in this rear trying to modify it? If i do the fabrication myself. I know i need axels and tubes. What else is needed? It has 373 gears and I have a JEGS cover to make it a little stronger. Will I have more in it than its worth? And what else can I do to make it stronger? And is there another route i can take that will be stronger for about the same price?

  13. #13
    Member
    Join Date
    Oct 2003
    Location
    Charlotte, North Carolina, Uni
    Age
    43
    Posts
    178

    white
    2002 TT Camaro

    Quote Originally Posted by nativetalon View Post
    Thanks. But how much will i have tied up in this rear trying to modify it? If i do the fabrication myself. I know i need axels and tubes. What else is needed? It has 373 gears and I have a JEGS cover to make it a little stronger. Will I have more in it than its worth? And what else can I do to make it stronger? And is there another route i can take that will be stronger for about the same price?
    does the 1980 rearend have a torque arm?

  14. #14
    Moderator Cutlass's Avatar
    Join Date
    Apr 2008
    Location
    Madison, WI
    Posts
    6,998

    1999 Formula WS6 M6-sold
    2001 Silverado Z71

    ^^^pretty sure they don't

  15. #15
    Junior Member nativetalon's Avatar
    Join Date
    Dec 2007
    Location
    pembroke, nc
    Age
    34
    Posts
    59

    silver & black
    2000 TA 1979 TA

    I guess what I'm saying is that I know the 8.5 is stronger than the 7.5. But by how much? A lot, or hardly any? I'm looking at dumping 500 to 1000 into it to make it as strong as possible. Am i wasting my time and money on this mod? The 9" or 12 bolts are what i would like to have. But, hard to afford 2500 to 3000 in a bolt in rear end. Should I save my money for a 9" or 12 bolt? And, if I plan to modify a rear end to fit. Is this the rear i should modify. Or do I need to look for a better one. Or can I buy a new one and modify it myself for maybe a little more than what i will have in modding this one?

  16. #16
    Junior Member nativetalon's Avatar
    Join Date
    Dec 2007
    Location
    pembroke, nc
    Age
    34
    Posts
    59

    silver & black
    2000 TA 1979 TA

    Quote Originally Posted by Darren P View Post
    does the 1980 rearend have a torque arm?
    No it doesnt. But I have two 7.5" rears and they both have one. Cant i fabricate one to fit? Or just buy one for around 150 or so?

  17. #17
    Moderator Cutlass's Avatar
    Join Date
    Apr 2008
    Location
    Madison, WI
    Posts
    6,998

    1999 Formula WS6 M6-sold
    2001 Silverado Z71

    The question is how are you gonna mount the torque arm to the 8.5" rear end?? Thats just about impossible. You gotta be a good fabricator. Might be easier to convert the car to a 4 link.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Rear LS1 98-02 Rear Disc Backing Plates/Calipers/Brackets
    By peetsjunkie in forum Parts Wanted / Trade
    Replies: 2
    Last Post: 10-02-2007, 09:53 AM
  2. Replies: 13
    Last Post: 07-08-2007, 10:42 AM
  3. Replies: 1
    Last Post: 06-19-2007, 08:06 PM
  4. Replies: 0
    Last Post: 05-25-2007, 11:37 AM
  5. Replies: 4
    Last Post: 05-19-2006, 05:39 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •