Changing from trailing arms to coil spring rearend

[72farmer]

I finally got to drive my 72 again after 5 years.I forgot the rearend has a whine when you level out at about 45-50 MPH.
I have a donor 72 GMC longbed.It has coil springs.How much trouble to put it in my 72 Chevy trailing arm set up?What are the chances that the yoke where ujoint slips in will be the same?

[special-K]

I'm not following you. Coil springs and trailing arms are both part of the same suspension design, also includes panhard bar to control lateral movement. The only other suspension being leaf spring.

[Andy4639]

Originally Posted by 72farmer

I finally got to drive my 72 again after 5 years.I forgot the rearend has a whine when you level out at about 45-50 MPH.
I have a donor 72 GMC longbed.It has coil springs.How much trouble to put it in my 72 Chevy trailing arm set up?What are the chances that the yoke where ujoint slips in will be the same?

Yes as Tim said you are talking about the same type of suspension here.

[57taskforce]

I have a feeling he meant to say leaf springs.

[roboticjunky]

I had to reread the post. His 72 truck has leaf springs and he has a donor 72 long bed with a coil spring set-up. He wants to switch from leaf springs to coil springs.


If the rear is whining, sounds like pinion bearing or the wheel (axle) bearings the axles ride on are bad.

[notsolo]

Look at your GMC donor frame coil spring perch's ( where top of spring attaches to the frame.) You may need to fab a couple up. I used 3/8 angle 3" x 3" and a 3/8 plate 5" x 5".

[Andy4639]

Originally Posted by 72farmer

I finally got to drive my 72 again after 5 years.I forgot the rearend has a whine when you level out at about 45-50 MPH.
I have a donor 72 GMC longbed.It has coil springs.How much trouble to put it in my 72 Chevy trailing arm set up?What are the chances that the yoke where ujoint slips in will be the same?

He may have but there is no mention of leaf springs here fella's!
Even the title says trailing arms.

[special-K]

Originally Posted by roboticjunky

I had to reread the post. His 72 truck has leaf springs and he has a donor 72 long bed with a coil spring set-up. He wants to switch from leaf springs to coil springs.

I read the post carefully and thoroughly. Read it again when it made no sense. Every time I looked at it it still said the same thing, then I posted. I just read it again to be sure and I have no idea where you got what you posted above unless you had a conversation with the thread starter somewhere other than on this tread. I'm still waiting for that person to come back with a clear question so we can give a clear answer.

[72farmer]

Sorry for the confusion.Donor 72 LWB GMC has leaf springs.Noisey rearend in in 72 SWB Chevy coil springs.

[Andy4639]

Originally Posted by special-K

I read the post carefully and thoroughly. Read it again when it made no sense. Every time I looked at it it still said the same thing, then I posted. I just read it again to be sure and I have no idea where you got what you posted above unless you had a conversation with the thread starter somewhere other than on this tread. I'm still waiting for that person to come back with a clear question so we can give a clear answer.

Agree, I don't know what he wants!

[roboticjunky]

Originally Posted by special-K

I read the post carefully and thoroughly. Read it again when it made no sense. Every time I looked at it it still said the same thing, then I posted. I just read it again to be sure and I have no idea where you got what you posted above unless you had a conversation with the thread starter somewhere other than on this tread. I'm still waiting for that person to come back with a clear question so we can give a clear answer.

I just assume he want to go from leaf springs to coil springs since that question comes up sometimes.

Sorry for the confusion.Donor 72 LWB GMC has leaf springs.Noisey rearend in in 72 SWB Chevy coil springs.

Now, we know what he wants.

[snipescastle2]

You will need the axle perches to weld onto your housing after you remove the leaf spring perches. Most vendors carry these, but make sure you have the correct pinion angle before they are welded, because you'll have more troubles with u joints and pinion bearings if you don't.not to mention the panhard bar stud provision. Here's a link to classic parts kit for your type conversion:

http://www.classicparts.com/mobile/1.../#.Vsm5mcnnaBY.

HTH,
Ben

[Grumpy old man]

Save yourself all the time and trouble of switching rears and just rebuild the noisy one .

[special-K]

In this situation a person has three choices:

1- Buy same rear used and bolt in

2- Adapt leaf to coil on rear already owned

3- Rebuild original rear

#1 is best for most. It's not complicated

#2 requires welding and fab skills...and you have to buy the pieces (not a large sum)

#3 requires advanced mechanical skills, a press, and a good bit of parts money

#2 & #3 can be hired out, but labor cost must be figured in

Oh, there is a #4. Use what you have, don't tear into anything, and just swap frames

[Andy4639]

I say rebuild the rear end. The easy thing to do. Maybe not to some but that's my opinion. You keep the truck all together and have a nice new gear set.