1989 Caravan Front Suspension Rebuild/Upgrade

[GLHS212]

Greetings!

Vehicle in question is a 1989 Caravan SE. I pulled the K-frame, lower control arms, spindles, and steering rack from a 1993 Caravan with the intention of installing at least some of those parts on the 1989. I also have a set of spindles, brake caliper carriers, and brakes with the 11" rotors from a 1992ish Daytona

My Questions to those who know -

1. I am planning on using the k-frame and the lower control arms for sure. That is how this whole thing started. My concerns are about the spindles - The ones from the 93 donor van are a bit corroded. I don't like the looks of the brake caliper carriers. What is the difference, if any, between the 1992 Daytona spindles and the 1993 minivan spindles. Can the Daytona spindles be used with the caravan K-frame and lower control arms.

1b. If using the Daytona spindles - should I use the 11" rotor, or back down to the 10.23" rotor and appropriate calipers. I don't mind having more brakes up front, but I am not planning on moving up to a larger master cylinder, so perhaps staying smaller is good. ??

2. Is there any advantage to using the newer power steering rack? Were there any improvements to the steering ratio on the minivans as there were on the cars? (According to Allpar, when the suspension was upgraded on the cars in 1991/1992 the cars got a tighter steering rack)

3. Torque specification on lower control arm mounting bolts

4. Torque specification on K-frame to body mounting points.

Thanks in advance!

Arlie

[turbovanman²]

If your going to use the 93 stuff, use it all, your geometery will be messed up using stamped knuckles with cast control arms.

Rack, not sure, different part number but never noticed anything driving one.

You'll have to use the 93 sway bar too.

If you use the knuckles off the car, you will need to run 20mm spacers otherwise you can't turn full lock as the wheels rub before you finish turning, the tie rod is in a different spot. The only difference for braking options on 91+ knuckles are the calipers and brackets, rotors and grand minivans or 15" wheel minivans have the larger bolt pattern.

You already have the larger MC.

Torque specs, tight, lol. I just use my impact gun.

[GLHS212]

20 mm adapter where, behind the wheel? That's .78 inches, pretty thick. Do you need to install longer wheel studs to compensate for the spacer? Hmm... Thanks! The spindles that I got with the K-frame are set up with a 5x100 bolt pattern now. I'm planning on replacing the wheel bearings while I've got it apart - seems that you can get a bearing with the hub for about the same price as the bearing itself. Seems to make sense. Now, if I need to install longer wheel studs too, this is certainly the time to do it.

Thanks again for the info!

[vipernbox]

If your going to use the 93 stuff, use it all, your geometery will be messed up using stamped knuckles with cast control arms.
.

Somebody correct me if I am wrong...


But the geometry changes happened like this..

The Lower ball joint position was moved forward in the cast control arms.. netting a small gain in castor.. Changing the LCA is all which is required to net this improvement..

The other geometry change was Raising the roll center by extending the bottom the the knuckle to change the angle of the LCA.



If using the old knuckle with the cast control arm.. He has the castor of the new design with the roll center height of the old design..

"messed up" seem like strong words..

It just won't be as improved as it could be.

[turbovanman²]

20 mm adapter where, behind the wheel? That's .78 inches, pretty thick. Do you need to install longer wheel studs to compensate for the spacer? Hmm... Thanks! The spindles that I got with the K-frame are set up with a 5x100 bolt pattern now. I'm planning on replacing the wheel bearings while I've got it apart - seems that you can get a bearing with the hub for about the same price as the bearing itself. Seems to make sense. Now, if I need to install longer wheel studs too, this is certainly the time to do it.

Thanks again for the info!

I use bolt on spacers, something similar to this-

http://www.ebay.com/itm/WHEEL-SPACER...413ddd&vxp=mtr

Somebody correct me if I am wrong...


But the geometry changes happened like this..

The Lower ball joint position was moved forward in the cast control arms.. netting a small gain in castor.. Changing the LCA is all which is required to net this improvement..

The other geometry change was Raising the roll center by extending the bottom the the knuckle to change the angle of the LCA.



If using the old knuckle with the cast control arm.. He has the castor of the new design with the roll center height of the old design..

"messed up" seem like strong words..

It just won't be as improved as it could be.

That is true but its still messed up, lol. He's better off just keeping the correct stuff together.

[GLHS212]

It is an interesting conundrum. I would like to take advantage of the improved suspension design of the post-91 era vans. So it makes sense to use the K-frame, LCA's, and spindles from the van. I'm going to hit the spindles with a sand or other media blaster and see what scales off. If the spindles are still good, then it is a win. If not, I have to either go with the car spindles or find another set of van spindles. I like the idea of a bit quicker turning, but I am not particularly fond of the idea of using the 20mm spacers (although they do look kind of cool). In the best of all possible worlds, I would use the van parts, pop in a set of Koni's and call it good. Unfortunately, I haven't found a set of Koni's and I don't really want to use anything that is available now. Having read the post about using the KYB AGX struts on the other TD cars, I'm intrigued at the idea of finding a set of struts that will fit the van that will be both better performing and appropriate for general daily driving.

That being said - any thoughts on other shock options, either from another make and model of car that will work well in the van, without lowering it too much, or something else like that - inserts, whatever, I'm open to suggestions.

Thanks again everyone!

Arlie

[vipernbox]

That is true but its still messed up, lol. He's better off just keeping the correct stuff together.

True 'nuff.. But then the rest of us are riding around with 'messed up' geometry..


But yeah.. given the choice.. Use the new knuckles.. and even more importantly use the new ones if you plan on lowering.. it becomes just that much more important.

[turbovanman²]

It is an interesting conundrum. I would like to take advantage of the improved suspension design of the post-91 era vans. So it makes sense to use the K-frame, LCA's, and spindles from the van. I'm going to hit the spindles with a sand or other media blaster and see what scales off. If the spindles are still good, then it is a win. If not, I have to either go with the car spindles or find another set of van spindles. I like the idea of a bit quicker turning, but I am not particularly fond of the idea of using the 20mm spacers (although they do look kind of cool). In the best of all possible worlds, I would use the van parts, pop in a set of Koni's and call it good. Unfortunately, I haven't found a set of Koni's and I don't really want to use anything that is available now. Having read the post about using the KYB AGX struts on the other TD cars, I'm intrigued at the idea of finding a set of struts that will fit the van that will be both better performing and appropriate for general daily driving.

That being said - any thoughts on other shock options, either from another make and model of car that will work well in the van, without lowering it too much, or something else like that - inserts, whatever, I'm open to suggestions.

Thanks again everyone!

Arlie

Why do the spacers turn you off? I've been running them for 4-5 years. Doing a proper u-turn is a nice feature instead of before having to do a 3 pointer,

If you want to lower it more than an inch you have to use car struts, FWD will be offering coil overs or inserts or figure out your own combo, otherwise use Van Koni's which are still available and lower a max of one inch.

[Juggy]

interested in selling the 89 cast minivan control arms??
I am in need of a set!!!

[RoadWarrior222]

89 I parted had stamped.

[Johnny]

Mini van's did not go to cast until 1991.

[GLHS212]

I don't have a logical reason not to like the spacers. I had some friends who had a bad experience with them when I was a younger human, back in the 1970's, but I am fairly sure that it was a problem with their mechanical skills, not with the spacers they were using I'll probably get over it That being said, I am not planning on lowering it much - where I live I really need the ground clearance. I haven't had much luck finding a set of the Koni struts for the vans, they had been discontinued some time ago. If you know of a place with a set, I'm all ears. I do like the idea of a real U-turn, that would be nice.

Thanks again to everyone for participating in this discussion. This is one of the reasons I love this forum. Good feedback, thoughtful responses, decades of experience with these cars all available to all of us. Go Us!

[turbovanman²]

I don't have a logical reason not to like the spacers. I had some friends who had a bad experience with them when I was a younger human, back in the 1970's, but I am fairly sure that it was a problem with their mechanical skills, not with the spacers they were using I'll probably get over it That being said, I am not planning on lowering it much - where I live I really need the ground clearance. I haven't had much luck finding a set of the Koni struts for the vans, they had been discontinued some time ago. If you know of a place with a set, I'm all ears. I do like the idea of a real U-turn, that would be nice.

Thanks again to everyone for participating in this discussion. This is one of the reasons I love this forum. Good feedback, thoughtful responses, decades of experience with these cars all available to all of us. Go Us!

www.fwdperformance.com

You can use rear Koni shocks, same place or I use adjustable Rancho shocks, they are good for changing loads, towing, racing etc as you can adjust them when you pull over.

[GLHS212]

I may have to upgrade the back shocks to Konis, I do like the idea of the adjustable ranchos you are using, in fact I read your earlier posts with great interest about you suspension work. At the moment, I'm deeper into the front end.

Quick question on using the front wheel spacers - according to one of the web sites selling the spacers, moving the wheels outboard in that fashion lowers the roll center. I thought that one of the reasons Mopar changed the suspension design was to raise the roll center. Any thoughts?

[turbovanman²]

I may have to upgrade the back shocks to Konis, I do like the idea of the adjustable ranchos you are using, in fact I read your earlier posts with great interest about you suspension work. At the moment, I'm deeper into the front end.

Quick question on using the front wheel spacers - according to one of the web sites selling the spacers, moving the wheels outboard in that fashion lowers the roll center. I thought that one of the reasons Mopar changed the suspension design was to raise the roll center. Any thoughts?

Thanks, spent alot of time trying things out.

Yes, it lowers the roll center, it helps keep it flat as it moves the wheels out.

Actually, it does, found some info-

These are hubcentric spacers that is specifically made to each vehicle; will fitted on your vehicle’s original hub perfectly without any gap. Wheel spacers move the wheel out from the hub, effectively widening the stance of the vehicle and lowering its roll center. This simple modification increases lateral stability, which in turn provides improved handling

http://www.h-r.com/gb/f_spurverbreiterung.php

http://www.tunersdepot.com/Toyota/Ca...s/items-1.html

[GLHS212]

Ok, spent some time cleaning things up this morning. At this time, it looks like the K-frame is usable. It also looks like the spindles will be usable. I'm going to replace the wheel bearings, ball joints, tie rod ends, control arm bushings with a poly set, sway bar bushings - keeping the stock sway bar until I can scrounge up a thicker one from a Caravan Sport or something like that. For brakes and rotors I'll order a set of replacement calipers for the 11" rotors with brackets, and install those. Does anyone know offhand if the rubber brake flex-lines from the 89 will bolt up to the 93 calipers? Still have to figure out the strut solution, but may be forced to use something substandard for the time being. I need to finish this job up in the next 3 or 4 days. Can't keep the current struts as they are truly shot, but might have to use some Monroe or KYB or something like that.

If I have to go that route, then what do you all think about the strut/spring/strut mount package that they are selling these days. For about 140 per side you get a bolt-in package. I'm thinking I order one for the 93 caravan with the v6 and it will have somewhat stiffer springs, if there are any options at all for spring stiffness. I will check to see if they have different part numbers for the 89 and 93.

Thanks again!

[turbovanman²]

I am running the later K-member so yeah, the 91+ calipers will use the original lines. Get the bushings from Polybushings.com, the Moog and other brands suck, I've tried them all, testing some nice ones right now from Johnny.

If your not lowering it, just use anything really, except the low end ones. I like the KYB's but the Gabriel Ultra's are a nice firm strut. The replacements units aren't bad but they are Sensatrac's which can be hit or miss. Go with the V6 and a/c, stiffest OE replacement spring. The sway bar you have is the thickest available, they didn't do different sizes from what I've found. I made a 1 1/4 one fit from a Shelby Z, but that's tons of work. PB offers sway bars. I would find a 2nd gen and take the rear sway bar and put that on, makes a nice difference.

[GLHS212]

Thanks again - I've got the bushings from Johnny coming today - Have the rear sway bar and brackets ready to install - thanks again for that set of photos and posts - and I'll check on strut availability this afternoon! I'll keep you posted!

[turbovanman²]

No problem.

[GLHS212]

Quick update for those following this thread - Got the 1993 K-frame cleaned up, found some surface rust, but no major structural issues. Everything came off and no bolts broke. I consider that a win. Stripped the minivan spindles of their brake caliper brackets and wheel hubs and wheel bearings. Those came off nicely, am installing new wheel bearings and hubs. Haven't decided for sure yet, but may paint the spindles with a spray can just to offer some protection. Got the ball joints out of the lower control arms and am in the process of removing the bushings. I have a set of bushings from Johnny at PolyBushings in a box waiting for their turn. The lower control arms cleaned up well. I should probably paint those as well. I am installing new ball joints and bushings on the LCA's. I have the new tie rod ends ready for the steering rack. I am going to install the rack that came with the 1993 cross-member, I think. According to Allpar, the valving is tightened up a bit. I also ordered a set of Moog poly bushings for the sway bar to replace the very rotted rubber bushings that came off the van.

The 60mm brake calipers and brackets will be at the store tomorrow, and will be matched to a set of 11" rotors. Hope that all clears the wagon wheel rims I've got my summer tires on. Haven't decided on brake pads yet, but will plan on using Rich's Hawk Pads next set.

So, things are coming together. Is there anything obvious that I'm missing? I think I've got it all covered, but it is always a bit worrisome when you completely disassemble the front of your car.

Thanks again, and Happy Motoring!