Concern over new suspension and drive line. Help is appreciated.

[Sherony]

I recently dug into my IIA to change the springs and shocks with a set of new standard (not parabolic) springs and shocks from our hosts. As the simple swap progressed, I uncovered a slew of issues that I have decided to fix from new swivel balls to freshly fabricated footwells. While under the truck, I decided to replace the rubber flex boot on the front propeller shaft, because there were just enough remnants of the previous one to serve as proof that it ever had a boot in the first place. I disconnected the nut on the prop. shaft without difficulty, marked the shaft on both sides, removed it, installed the rubber boot, and reassembled. With the new springs and shocks and freshly cleaned front axle installed, the prop shaft would not reach the front differential. Figured I could add a little slack to the retaining nut on the shaft, but in order to make it reach the front diff, the nut had to be removed completely... obviously not going to work... I found a compromise, but it concerns me.
By putting a floor jack under each spring and taking the vehicle weight off the frame and placing it on the front springs, the shackles would shift back a fuzz, the prop shaft would fit, and the retention nut would thread on about 2/3 of the way down. This concerns me because I feel that if the truck hits a decent bump, the front suspension will be yanking on the transfer case. If anyone has any insight, I would love to hear it. Anything from, "you did it wrong" to "stop worrying, it works".





PS. How important is the 12lbs of drag when re-installing the swivel balls? The shims that came out of mine seemed to be in good shape and i kept them organized planning to just re-install them in the same order. Do I need to re-calibrate them? If so, what tool do I use to measure 12 lbs. of drag on there?

[I Leak Oil]

A) The front shaft should extend far enough to reach if everything is put back together correctly. It should have extra travel.

B) If you rebuilt the swivels you need to reset the preload on them. Simply reinstalling the original shims with new pins and bearings probably won't be good enough. If the preload isn't right you're going to have steering issues and accelerated wear in your brand new parts.

[slorocco]

I agree with the above on both counts. The driveshaft should have extra travel in it in order to avoid the problem that you mentioned. Try disconnecting the rubber boot and stretching the driveshaft out all the way. Maybe that is what is preventing full extension? BTW, any chance you have the front and rear driveshafts switched around? I can't remember which one is shorter on an 88.

On the swivels, you are definitely better off with the correct thickness on the shim pack. To check the preload I just used a fish weight scale from the local tackle shop, hooked it on the steering arm, and pulled.

[TeriAnn]

BTW, any chance you have the front and rear driveshafts switched around? I can't remember which one is shorter on an 88..

It has been almost 35 years since I've had my 88, but if my memory is still firing on at least one cylinder I believe the short one is the rear propshaft.

With the vehicle sitting level, the static length between the two flange mounting positions should be the propshaft length at one half slip joint extension.

When you assembled the springs, did you leave the fixing bolts a little loose? You should have the mounting bolts & shackle bolts a tad loose, drive the truck around the block to let the springs & shackles settle into their proper position then tighten the bolts up. If you have not done it already, do it before attaching the front prop shaft. It could be that the springs are sitting high (increasing flange to flange distance) because they are not settled in.

But first verify that you do not have propshafts reversed.

And yes you do need a pull spring scale and a fish scale that goes up to about 20 lbs fits the bill. As the steering wears, you check the spring pressure on occasion and remove shims as needed to retain the correct tension. So your old shim pack could be shy a could of shims from what you need.

[SafeAirOne]

I don't think anyone mentioned it, but in the book there is a procedure to set the spring-to-shackle angle before tightening the shackle bolts so that you don't load the bushing rubbers incorrectly. This could have an impact on spring heght initially, though I think there should still be some driveshaft extension room left even if you performed this procedure incorrectly.

[Sherony]

Thanks all for the replies. I know I don't have the propshafts reversed because I have not removed the rear one yet, and the front was never unbolted from the transfer case. The rubber boot is not even clamped down yet, so I know that is not the problem. Sounds like i need to loosen the shackles, drive it a bit, and hope these proline springs settle into a healthy spot.

[slorocco]

Something still ain't right then. That drive shaft should be able to bolt up with room to spare anywhere in the full range of the suspension travel. Otherwise, as you stated to begin with, it's going to be bangin on the pinion bearing/seal and on the t-case at full droop.

[I Leak Oil]

I couldn't view your picture of the shackle from my PC at work this morning but I can now at home. The shackle is toggled over in the wrong direction. It should be straight up and down at max, 45 degree rear rake at rest. Looks like you have a forward rake in that picture. What does it look like with the weight on the suspension?

[Sherony]

In the picture, the entire weight is on the springs. The jack stand in the background is just a safety precaution, it is not actually touching the frame.

Would it help to set these springs if I put them on my hydraulic press and flatten them out a fuzz?

[I Leak Oil]

Sounds like your shackles may have gotten toggled over in the wrong direction. Loosen the shackle bolts and remove one from each side. Be careful as the spring may be under compression. With the bolts out, jack up the axle a little bit until the shackles have a rear rake to them (spring end of the shackle to the rear of the truck). Reinstall the bolts. This should allow the axle to move rearward and allow the drive shaft to bolt up correctly.

[Sherony]

I actually tried this, and the spring lifted the whole vehicle before I could get the shackle to mount in a rearward position.

[bkreutz]

I would think something is wrong with the springs, if the propshaft fit correctly before this exercise then the only thing left is the spring. Did you get them on the proper end of the truck, if so then maybe compare the measurements of the springs you took off to the ones you installed. Maybe you were sent the wrong ones?

[ignotus]

This may be dumb but are you sure that the axle centering pin is in the hole? Just thinking of what might be off.

gene

[Sherony]

I am positive the centering hole is correct, and I spoke with our hosts to make sure these are the right springs. Last night I disconnected the shackles again in an attempt to get these spring in position. The pics below were taken with the entire weight of the front of the truck resting on the springs. I have the front bolts attached but not tightened and a floor jack under the U-bolt plate. These springs have flexed as far as they can under the weight of the vehicle. The only other points holding the truck are a pair of jack stands holding the rear bumper. Any other points of interests that anyone can identify?

[yorker]

I think they just need to lose some arch. Sometimes springs come with a lot more arch than they need- I'm not sure why? Put them back together using the manual's instructions like Safeairone mentioned and let it sit with weight on the front.