Register    Login    Forum    Search    FAQ



Board index » TECHNICAL » Drivetrain Technical




Post new topic Reply to topic  [ 12 posts ] 
Author Message
 Post Posted: Sat Dec 26, 2015 6:13 pm 
Offline
Moderator
User avatar

Joined: Mon Jun 02, 2003 11:15 pm
Posts: 14569
Location: Catalina, AZ
So I finally located a suitable T-5 today, still trying to get ahold of the seller. In the meantime I had a question about the driveshaft. I've read it needs to be shortened, but I'm considering getting a larger diameter factory driveshaft. I've seen aluminum shafts in later ('90s+) full size trucks/SUVs, so I was thinking of finding one cheap and having a local shop cut/balance it to fit the car. Does anyone have a length (u-joint to u-joint) required for a T-5/7.5" combination?

_________________
Image
MR.com Facebook page
'92 Sierra - EBL/TBI-fed Vortec 383/700R4/3.08
'87 Fiero GT - 2.8/5-speed
'78 Malibu - Vortec 350/4-speed (for now)


Top 
 Profile  
 
 Post Posted: Sat Jan 16, 2016 2:17 pm 
Offline
MalibuRacing Junkie
User avatar

Joined: Sun Oct 21, 2007 8:07 am
Posts: 4375
Location: Lederach
The u-joint centerline distance is 3 inches shorter than the stock Malibu driveshaft.


Top 
 Profile  
 
 Post Posted: Fri Apr 08, 2016 1:03 pm 
Offline
Moderator
User avatar

Joined: Mon Jun 02, 2003 11:15 pm
Posts: 14569
Location: Catalina, AZ
Any idea what that might be? I found a Craigslost ad with a 2nd gen driveshaft listed but it has a measurement, not what engine/trans it had.

_________________
Image
MR.com Facebook page
'92 Sierra - EBL/TBI-fed Vortec 383/700R4/3.08
'87 Fiero GT - 2.8/5-speed
'78 Malibu - Vortec 350/4-speed (for now)


Top 
 Profile  
 
 Post Posted: Sat Apr 09, 2016 8:39 am 
Offline
MalibuRacing Junkie
User avatar

Joined: Sun Oct 21, 2007 8:07 am
Posts: 4375
Location: Lederach
I just looked at my collection. The stock driveshaft is 52.5 inches between centerlines of u-joints. The T5 shaft is 49.5 inches between centerlines of u-joints.


Top 
 Profile  
 
 Post Posted: Sat Apr 09, 2016 2:22 pm 
Offline
Moderator
User avatar

Joined: Mon Jun 02, 2003 11:15 pm
Posts: 14569
Location: Catalina, AZ
Ok I may have to get ahold of this guy then, the driveshaft he listed says 49" 8)

_________________
Image
MR.com Facebook page
'92 Sierra - EBL/TBI-fed Vortec 383/700R4/3.08
'87 Fiero GT - 2.8/5-speed
'78 Malibu - Vortec 350/4-speed (for now)


Top 
 Profile  
 
 Post Posted: Sat Apr 09, 2016 2:42 pm 
Offline
MalibuRacing Junkie
User avatar

Joined: Sun Oct 21, 2007 8:07 am
Posts: 4375
Location: Lederach
There is a reason why GM added the additional 1/2 inch. If the shaft is too short, you will have less yoke engagement with the transmission. I don't think 49 is a good compromise for 49.5.


Top 
 Profile  
 
 Post Posted: Sat Apr 09, 2016 5:37 pm 
Offline
Dragway Regular

Joined: Mon Mar 10, 2008 5:00 am
Posts: 1274
Location: Cincinnati, Ohio
But being lower than stock wouldn't he gain that 1/2 inch?

_________________
1980 Malibu coupe 468/th350


Top 
 Profile  
 
 Post Posted: Sat Apr 09, 2016 6:56 pm 
Offline
MalibuRacing Junkie
User avatar

Joined: Sun Oct 21, 2007 8:07 am
Posts: 4375
Location: Lederach
That would require getting under the car and measuring properly. If the shaft is shorter than stock, what will happen at full suspension drop? A shaft that is 1/2 inch too short could be a problem and bind. Be smart and get the proper length shaft.


Top 
 Profile  
 
 Post Posted: Tue Feb 14, 2017 7:05 pm 
Offline
Moderator
User avatar

Joined: Mon Jun 02, 2003 11:15 pm
Posts: 14569
Location: Catalina, AZ
I'll do 3" for now. I picked up a B-Body 8.5" a couple weeks ago and plan on using it, but for now I need to get it to driving capability asap for the wedding (not sure how much work the 8.5 will be to fit yet). Plus I may be attempting to build a 3-link setup using the upper ears and adding a watts link.

Way I see it, regardless if it's lowered or not, the bumpstop is still in the same spot, and like you said about the extension of the suspension, may as well not take the chance.

_________________
Image
MR.com Facebook page
'92 Sierra - EBL/TBI-fed Vortec 383/700R4/3.08
'87 Fiero GT - 2.8/5-speed
'78 Malibu - Vortec 350/4-speed (for now)


Top 
 Profile  
 
 Post Posted: Tue Feb 14, 2017 9:01 pm 
Offline
MalibuRacing Junkie
User avatar

Joined: Sun Oct 21, 2007 8:07 am
Posts: 4375
Location: Lederach
When you use that 8.5-inch rear, your driveshaft will need to be shortened another inch.

What year B body is the rear from?

How much wider is it than the 1978 rear?


Top 
 Profile  
 
 Post Posted: Tue Feb 14, 2017 9:23 pm 
Offline
Moderator
User avatar

Joined: Mon Jun 02, 2003 11:15 pm
Posts: 14569
Location: Catalina, AZ
It's probably a few inches wider, my plan is to have it shortened to stock width and have the G-Body lower arm/shock mounts attached. I'm not sure of the geometry yet on the upper arms... I've seen some say they're the wrong angle, I've also seen some say the arms can be shortened, but I'm not sure how that would affect pinion angle movement (shorter uppers by 3", stock length G-Body lowers).

_________________
Image
MR.com Facebook page
'92 Sierra - EBL/TBI-fed Vortec 383/700R4/3.08
'87 Fiero GT - 2.8/5-speed
'78 Malibu - Vortec 350/4-speed (for now)


Top 
 Profile  
 
 Post Posted: Wed Feb 15, 2017 8:52 pm 
Offline
MalibuRacing Junkie
User avatar

Joined: Sun Oct 21, 2007 8:07 am
Posts: 4375
Location: Lederach
If the upper control arm brackets are at the wrong angle, I wonder if a D-shaped control arm could be fabricated, so that the curve of the D could allow the arm to connect to the brackets squarely.

It would be interesting if the lower arm brackets were already in the correct location.


Top 
 Profile  
 
Display posts from previous:  Sort by  
 
Post new topic Reply to topic  [ 12 posts ] 

Board index » TECHNICAL » Drivetrain Technical


Who is online

Users browsing this forum: Bing [Bot] and 1 guest

 
 

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: