Opel GT Forum banner

1 - 20 of 61 Posts

·
Senior Contributor
Joined
·
903 Posts
Discussion Starter #1
Here are a few pics of the mods I performed for my Toyota axle installation in a GT. The first picture shows the axle shortened by .600". I later removed another .200". Housing has been narrowed by 1. 7". More to come as I complete...

-Travis
 

Attachments

·
Super Moderator
Joined
·
13,617 Posts
Nice job Travis, it's looking good. You should have tried to get a 2wd rear axle, the axle flanges and bolt patterns are different, there would have been less machining involved to get the Opel bolt pattern (the 2wd uses 5 x 4.5"). Regardless, it's gonna be sweet. Send more pics when you attach the trailing arms, etc to the housing!

Bob
 

·
Senior Contributor
Joined
·
903 Posts
Discussion Starter #5
I didn't realize they were different. The toyota sites I found on the web, which are mostly aimed at muddin', said that all the pre '85 axles were the same other than ratios and extra gussets in '84 and '85 on the third member. It does however have the 4.10 ratio which should work well until I have the time/money to get the 4.88s and LSD.

I should have spring buckets on this weekend.

I don't suppose you happen to remember if the e-brake lever on the back of the backing plate is supposed to be toward the front or rear of the axle? Not really a big deal as I can swap them later if needed...

-Travis
 

·
Super Moderator
Joined
·
13,617 Posts
I don't recall offhand about the e-brake lever, but I'll check in the AM and let you know. I have three of the Toyota axles out in the barn slated for future Opel projects.....

Bob
 

·
Super Moderator
Joined
·
13,617 Posts
I couldn't get a rusty drum off any of the rear axles, but the e-brake cable enters from the front (like an Opel), so this means it should be pulling on the rear shoe to apply the e-brake, again like an Opel. Hope this helps.

Bob
 

·
Registered
Joined
·
47 Posts
very nice, have to let me know how the single driveshaft works, I like that idea more than the two piece with the doughnut, I don't like those things, they always went out on the trucks I worked on.
 

·
Super Moderator
Joined
·
5,808 Posts
Axel Conversion

Umm, I'm no suspension expert, but are you planning on significantly modifying the axle linkage that locates the new differential? It appears you are planning on dispensing with the stock torque tube, but are retaining the stock spring mounts and trailing arm points. With a standard GT rear suspension, I believe the torque tube acts as a "third" (and fourth) link, helping (although poorly) to keep the differential from winding up under torque. Hence it's name. If you only install the stock trailing arms and the Panhard rod, I don't think you will be very happy with the results. But if you are installing upper control links (or some other kind of locating arm) it will be neat to see the pictures. Good luck
 

·
Senior Contributor
Joined
·
903 Posts
Discussion Starter #14
Yes, the torque tube will not be used. My initial plan was to construct a simple torque arm. Unfortunately, it just wasn't going to be all that simple. At full bump the axle essentially tucks up into a recess in the floor and makes attachment of a triangulated arm very difficult. I decided a few days ago to go to a three link configuration with a single short upper link. I've built the link and the body and axle mounts and plan to weld them in place this evening. Although I have used the stock spring buckets I will be relocating the trailing arm links to both tune for neutral roll steer as well as distance them from the upper link for strength. The shock mounts will also be moving to prevent my shorter springs from falling out at full droop and improve their effectiveness. The stock shock layout is not very effective, especially when lowered

-Travis
 

·
Senior Contributor
Joined
·
903 Posts
Discussion Starter #15
Here is a shot of one of my lower links. Bar is length adjustable and it's mount on the axle has some adjustment for roll understeer/oversteer/neutral as well as compensation for any ride height adjustments which are now possible due to the three link configuration.

-Travis
 

Attachments

·
Registered
Joined
·
47 Posts
is it just me, or does your pivot bushing seem a bit angled? wouldn't that cause a binding problem through the range of motion of the suspension? Just curious since I'll have to be doing almost the same thing.
 

·
Senior Contributor
Joined
·
903 Posts
Discussion Starter #18
It's not just you Maddyn, the bushing is angled relative to the arm. This is because the arm will not be running perpedicular to the axle as in the stock configuration. I had to angle the arm inward soewhat to get around the spring bucket. If your using coil overs this wouldn't be necessary.

-Travis
 

·
Registered
Joined
·
47 Posts
ok, gotcha.. yeah that makes a little more sense. You couldn't resign a bracket off the spring buckets that would work? Also are you lengthing the control arms any, or are those the same length as stock?

Looks like it's comming along good though, can't wait to see the finished product.
 

·
Senior Contributor
Joined
·
903 Posts
Discussion Starter #20
The length between centers is around 24 inches. i havn't actually measured it. It's effective length is slightly shorter due to it being angled. I'm not sure how long the stock arm is, but i'd guess around 2/3.

With a three link or even four link you really need to get the lower connection to the axle down below the axle and with a mount as reasonably long as possible. If you look at the amount the axle is allowed to travel in rotation due to compliance (especially the poly bushing) it should be clear why you can't keep the mount where it was. Also the length of the mount as measured perpendicular to the arm directly affects the forces on the arm. The longer the mount, the less forces on the arm and body and the less deflection of the poly bushing. Same is true of the upper mount.

BTW, with the stock suspension the rotational forces are transmitted through the torque arm. This is why the stock mounts can be where they are.

I can't wait either. My motor should be ready around the end of the week which means I need to start assembling it and not working on the suspension. I need to get this done in the next few days:)

-Travis
 
1 - 20 of 61 Posts
Top