Close



Page 1 of 2 12 LastLast
Results 1 to 25 of 39
  1. #1

    Default Another 8.8 swap question

    Ok so started pulling my 7.5 on my 78 futura. Will the driveshaft be the correct length and the correct flange to bolt onto a 87 8.8?
    Or are these a no issue direct swap?
    I did lots or reading and one guy said the flange is different and the shaft is too long and will damage the trans .

  2. #2

    Default

    Are you sure you have a 7.5? Mine had a 6.75, which uses a different driveshaft. If it really is a 7.5, you won't have any issue with the driveshaft.

    Sent from my XT1650 using Tapatalk
    Brad

    '79 Mercury Zephyr ES 5.0L GT40 EFI T-5 (Mustang LWB)
    '17 Ford Transit Connect Titanium LWB
    '14 Ford Fusion SE Manual

  3. #3

    Default

    FWIW on my 1980 cobra swap I found that the 8.8 pinion flange sits about 1/2" closer to tranny than the 7.5 so may be a little tight depending on your combo etc.

    Also in my case because I had a C4 auto driveshaft with 7.5 (converting to T5 and 8. it needed to be shortened by about 1.5"in total. Not a real big deal took it to a driveline shop and they shortened and rebalanced and installed new u joints for a couple hundred bucks which i thought was quite reasonable. The way I understand it the C4 and 4 cylinder combinations on these cars had longer driveshafts by about 1".

    In my other car I am running a standard 45.5" motorsports aluminum driveshaft with my V8, T5, and 8.8 and it all fits fine.

  4. #4

    Default

    Quote Originally Posted by at_the_junkyard View Post
    FWIW on my 1980 cobra swap I found that the 8.8 pinion flange sits about 1/2" closer to tranny than the 7.5 so may be a little tight depending on your combo etc.

    Also in my case because I had a C4 auto driveshaft with 7.5 (converting to T5 and 8. it needed to be shortened by about 1.5"in total. Not a real big deal took it to a driveline shop and they shortened and rebalanced and installed new u joints for a couple hundred bucks which i thought was quite reasonable. The way I understand it the C4 and 4 cylinder combinations on these cars had longer driveshafts by about 1".

    In my other car I am running a standard 45.5" motorsports aluminum driveshaft with my V8, T5, and 8.8 and it all fits fine.
    Will get it mocked up this weekend. We have a balance machine at work and can build a driveline so no big deal.
    I want to replace the top bushings and they are 4-5 days away so will hopefully be together before the snow..

  5. #5

    Default

    Quote Originally Posted by ZephyrEFI View Post
    Are you sure you have a 7.5? Mine had a 6.75, which uses a different driveshaft. If it really is a 7.5, you won't have any issue with the driveshaft.

    Sent from my XT1650 using Tapatalk
    Should be a 7.5 the 4 and 6 cylinders had a smaller rear gear. My brother has a 200 six in his 78 and I think it is not a 7.5
    Probably pull the axle and compare thr flange and measure the differance in the housing to the flange and there are many variables here with t5 c4 this amd that.
    One guy said he put his together and screwed up his tranny in 20k as the driveshaft was too long.
    Some say thr flanges dont even bolt up.

  6. #6

    Default

    I don't know if there's any rhyme or reason to which engines got what rear, except maybe the V8s definitely got the 7.5.

    Especially in '78. There were all sorts of odd differences between the early and later cars.

    Another deciding factor is which k-member you're using, V8 or 6.

    I got a driveshaft out of a 3.8 C4 LTD wagon once for my T5 8.8 Zeph and it bolted right in.

    Sent from my XT1650 using Tapatalk
    Brad

    '79 Mercury Zephyr ES 5.0L GT40 EFI T-5 (Mustang LWB)
    '17 Ford Transit Connect Titanium LWB
    '14 Ford Fusion SE Manual

  7. #7

    Default

    Quote Originally Posted by ZephyrEFI View Post
    I don't know if there's any rhyme or reason to which engines got what rear, except maybe the V8s definitely got the 7.5.

    Especially in '78. There were all sorts of odd differences between the early and later cars.

    Another deciding factor is which k-member you're using, V8 or 6.

    I got a driveshaft out of a 3.8 C4 LTD wagon once for my T5 8.8 Zeph and it bolted right in.

    Sent from my XT1650 using Tapatalk
    Its a factory v8 c4 car. Will see what happens and report back.

  8. #8

    Default

    I'll be keeping track of how this goes for you 78futura...I have the same thing. A 302/C4 factory car, and going from 7.5 to 8.8. The flanges look the same, so I hope there's enough room in the tranny to allow movement should there be any minimal differences.

  9. #9

    Default

    The flanges are the same on 8.8 and 7.5 and the driveshaft will bolt up just a question of how much length.

    If the driveshaft is too long you may not even be able to get it installed as you need to push the yoke in to the tranny enough to clear the pinion nut and get the rear flange in place without squishing the transmission seal.

    IIRC you should have about 1" of travel when the car is sitting level on the ground...so that when driving and going over bumps the yoke going into the tranny can move that far before bottoming out or interfering too much with the with the seal etc. There may also be differences in how long the actual yokes are between models so another consideration which would make a difference.

    My 1980 cobra originally had 255 and C4 with 7.5 and I needed to shorten the driveshaft for sure. I assume your cars will most likely be the same.

    That is what I run into anyway...hope that helps !!

  10. #10

    Default

    Just re-read some posts. If you guys are keeping the C4's and not going to T5 or something different then I think it may just fit although I swear the 8.8 flange will sit about 1/2" closer to the tranny.

  11. #11

    Default

    Quote Originally Posted by at_the_junkyard View Post
    Just re-read some posts. If you guys are keeping the C4's and not going to T5 or something different then I think it may just fit although I swear the 8.8 flange will sit about 1/2" closer to the tranny.
    Yea that's what I was anticipating to be the situation. That the nose of the pinon is likely a little further towards front of car relative to the spring perches, and likely some fraction of an inch. Hopeful that whatever travel there is in the tailhousing can accommodate and can keep driveshaft as is.

  12. #12

    Default

    If its a bit short, Lincoln's ans f-150's have about an inch longer yoke.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  13. #13

    Default

    Quote Originally Posted by Haystack View Post
    If its a bit short, Lincoln's ans f-150's have about an inch longer yoke.
    Ok I took it all apart. What a s.o.b. everything siezed.
    Differneces are the 8.8 is 1/2" longer than the 7.5
    The brake lines are the same to the diff but from the T out they are different for the bend around the quad shock mounts.
    I need to order brake lines and lower rear bushings and spring isolators 2 more weekends for parts to get gathered up.
    I wonder if I should shorten the shaft? Hmmm... it is free to do just time..

  14. #14

    Default

    Heres an idea. There is about 2" of the slip end on the tranny that does not go in. Why not just cut the end of the slip end off 1/2" or whatever and clean up the splines? Taper the end do it does not screw the trans seal? Grest idea or hillbilly horsecrap?

  15. #15

    Default

    Looks like I need a 1990 mustang 4cylinder rear brake line that goes to the T.
    The 78 futura 302 line comes out of the floor to a female hose to the T that connects to the passenger side exactly the same as the 8.8.

  16. #16

    Default

    I've cut the end off of a yoke before, that's how I figured out the Lincoln yokes are longer.
    I hucked a ujoint on the freeway acrossed the street from a junkyard. Whole yoke was just gone, never did find it. No foxes in the yard, ended up pulling a town car driveshaft. Walked to an AutoZone with the driveshaft and pressed in a new ujoint. When I went to throw it in the car, it was too long. I hacksawed the end off. The last inch maybe inch and a half had no splines. Put another 20-30k miles on it without issue.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  17. #17

    Default

    Ok kimda screwed right now. I can not find rear lower suspension bushings for my car.. can only find poly no rubber.
    Moog makes an upper that gives you 2 bushing to do both ends so you have to buy 2 kits but no one makes a lower in rubber for a fox body car.. fn mindblowing.. people just never do those just use zip ties when they are screwed? Unreal!

  18. #18

    Default

    Yup, pretty sure poly is your only choice. I will say I have new poly on the bottom and new rubber on the top and wheel hop is nearly gone

  19. #19

    Default

    It alot of money to do. Have to buy rubber kits just for the diff housing and a complete poly kit just for 2 bottoms... oh well another 150 bucks...

  20. #20

    Default

    I used all 4 bottoms, and the uppers weren't too bad at rock auto. They make an install tool for the rubbers. I used some random pipe pieces, sockets and all thread to replace the rubbers. You need to put some sort of block into the upper arm so you dont crush it. The lowers you need to leave the metal jackets in for the poly bushings. Some will drill them, I torched mine. Just make sure you get enough grease on the poly pieces when you go back together so it doesn't squeak.

  21. #21

    Default

    Quote Originally Posted by 2nd chance cobra View Post
    I used all 4 bottoms, and the uppers weren't too bad at rock auto. They make an install tool for the rubbers. I used some random pipe pieces, sockets and all thread to replace the rubbers. You need to put some sort of block into the upper arm so you dont crush it. The lowers you need to leave the metal jackets in for the poly bushings. Some will drill them, I torched mine. Just make sure you get enough grease on the poly pieces when you go back together so it doesn't squeak.
    I just want to replace them cause the bolts were siezed in and i had to cut the bolts with a grinder to get the diff out.
    Just need two lower rear and one upper.
    Of course will have to buy a kit with them all cause no such thing as seperating the bushings in different kits..
    The parts stores can not find me spring isolators looks like everything will be sourced online.. american muscle does not sell bushing kits just spring isolators... i think summit sells kits.
    Will figure out whats the cheapest.. already wasted 70 bucks on a bushing kit with shipping that does one upper arm.. was supposed to do both upper bushings on the diff...try again..
    Thats what happens when I order parts over the phone without seeing them.

  22. #22

    Default

    Quote Originally Posted by 78futura View Post
    I just want to replace them cause the bolts were siezed in and i had to cut the bolts with a grinder to get the diff out.
    Just need two lower rear and one upper.
    Of course will have to buy a kit with them all cause no such thing as seperating the bushings in different kits..
    The parts stores can not find me spring isolators looks like everything will be sourced online.. american muscle does not sell bushing kits just spring isolators... i think summit sells kits.
    Will figure out whats the cheapest.. already wasted 70 bucks on a bushing kit with shipping that does one upper arm.. was supposed to do both upper bushings on the diff...try again..
    Thats what happens when I order parts over the phone without seeing them.
    Ok can not find lower bushings of any kind anywhere rock auto you name it..
    Anyone have a part number for a lower axle bushing kit?
    Maybe the only way is to buy a complete new arm from 115-400usd.
    I have from 5-9pm tonight searching everywhere..

  23. #23

    Default

    Yes I also noticed there are not a lot (or any) options for just buying the rubber bushings when I did my upgradesas well. So unfortunately you are forced to either rebuild your existing with new poly bushings or spend the $$ and get new arms. I have done it both ways on my 1980 cobras.

    My opinion it is a very messy and labour intensive job to remove and clean out the old rotten and seized rubber bushings while retaining the metal shells to use a new poly set....but hey if your on a budget your on a budget !! The other car I ended up just spending the money and bought some new MM adjustable arms (very nice units but not cheap relatively).

  24. #24

    Default

    Name:  20180910_090933.jpg
Views: 118
Size:  93.9 KBName:  20180910_090440.jpg
Views: 118
Size:  68.2 KB these are my two receipts for bushings, o Reilly and summit. O'Reilly is the rubber bushings for the uppers and the summit is the bushings and spring insulators (I believe) for the rear. They were prothane. Prothane was very helpful in the phone. I told them what I needed then they gave me the numbers to go buy them. I chose summit. I think one of those isolators is the front spring

  25. #25

    Default

    Quote Originally Posted by 2nd chance cobra View Post
    Name:  20180910_090933.jpg
Views: 118
Size:  93.9 KBName:  20180910_090440.jpg
Views: 118
Size:  68.2 KB these are my two receipts for bushings, o Reilly and summit. O'Reilly is the rubber bushings for the uppers and the summit is the bushings and spring insulators (I believe) for the rear. They were prothane. Prothane was very helpful in the phone. I told them what I needed then they gave me the numbers to go buy them. I chose summit. I think one of those isolators is the front spring
    Cool man thanks.
    The top receipt looks like for upper moog axle bushings. Here they are 2x the money. I paid that for one.
    The other kit looks like the prothane rear diff kit that does all the rear. I should be able to use that part number with my parts store to order them as takes weeks from summit due to the border and shipping.

Page 1 of 2 12 LastLast

Posting Permissions

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