Manta Question

[neuropel]

I have a 1974 Manta with stock suspension, but I'm running 195/50/15 tires on 15x7 ROH Snyper wheels (temporarily). When driving at highway speeds, I hear tire rub in the fenderwells when going over uneven areas or bumps. At first I thought it was the tires rubbing the lip in the outer fender wells, but the lip has been pulled up out of the way so there's at least half an inch of clearance all the way around the fender (I can slide my hand all the way around between the fenderwell and tire). Is that enough clearance? I'm going to install new shocks because I have NO idea how old the existing ones are. I'm going with Bilstein B46-1099-HO (for an '86 Nissan 720 2wd pickup) on the front and Rancho 99168 9-way adjustable shocks on the rear.

I know this will change the handling of the car, but will it also likely get rid of the wheel rub? I have no other changes planned at this time, so I'll be retaining stock springs and bushings. It has around 50K original miles, so they may even be original! If this shock combo works well I'll be duplicating it on a 73 Rally but with the addition of poly bushings and some 275/170 springs (with a 2" drop I believe) that I got on a parts car from Duane Foley. I'll be moving back to 13" wheels/tires as soon as I can get my set of Libre wheels cleaned up. I'm probably going with some 205/60-13 Cooper Cobras, mainly because I like the white letter look and they're the only ones out there I can find. I also like the tread design.

I'd appreciate comments or suggestions from experienced Manta guys on what changes I can expect with these suspension changes in regard to ride (is it going to beat me to death?) and handling versus stock.

Last question...I have a rear suspension poly bushing kit from OGTS that I had for a GT but never installed it. Am I correct in assuming it will work on a Manta rear suspension as well? Would there be any issues to going ahead and installing that kit on the Manta while I'm already there doing shocks, bearing in mind that the front will retain the stock rubber bushings?

Thanks!
Todd K.

[GTJIM]

Because of the Panhard rod which locates the diff from side to side the diff actually moves across the car as the suspension is compressed.
Depending on how the Panhard rod is set up this can be in either direction.
When the car is stopped there appears to be enough clearance but it disappears as the suspension moves. Throw a few bags of sand or cement into the trunk and compress the suspension until the Panhard rod is parallel to the ground - that is when the maximum movement of the diff - sideways - is reached. Now check the tyre clearance on both sides.

[neuropel]

Gotcha!
I'll try that.

[GTJIM]

Just 'watched' the diff move in my head!

The maximum movement in the other direction across the car occurs when the suspension is fully compressed and/or fully extended so the wheel clearance can be checked in this case by jacking the car up, at the rear, under the body work so that the diff hangs down. Just as the wheels leave the ground will be the point of maximum travel sideways in the other direction.
HTH

[Paul]

Todd,

1. The ride will be stiffer, but shock choice will determine ride harshness.

2. When you lower the car be sure to cut the rubber bump stop for the front suspension in at least in half.

3. When you lower the car you really should shorten the length of the Panhard bar. How? by making an adjustable one. Not too hard. There is a thread where RallyBob gives very good instruction on what to buy. If you need help finding the parts, I can find my list of the parts I bought for mine.

4. The rear Poly bushing set fits both the GT and Manta according to OGTS. My suggestion on poly bushings is to install grease fittings when you put in the new bushings.

5. Poly bushing tend to bind. This will happen as the car rolls in a tight corner. The rubber bushing can rotate/twist in two directions, the poly can only really move in one direction. I have not done it yet, but I plan to put rubber bushings back in for the poly bushings where the trailing arm connects to the spring bucket.

[neuropel]

Paul,

I have a good adjustable panhard rod that I bought from a fellow member...YOU!
I'm planning on using it on the lowered car.
Sounds like the shock changes I have for the current car will stiffen up the ride a bit...that's ok. I'll hold off on using the poly bushings until I drive it a bit with the new shocks. Switching back to 13" tires/wheels may solve the rubbing issue (I'll still check it per Jim's recommendations).

Thanks for the comments guys! Any others are certainly welcomed!

Todd

[Paul]

DUHHHH

[Paul]

Is the rubbing sound coming from the front tires or rear.......

[Paul]

Todd,

Another thing you can do when you are replacing the springs is to move the suspension through the full range of travel with the springs out. I did the same thing to check shock travel and internal bottoming. If you perform this exercise with the tires on, you can check for rubbing. Simply place the car on jack stands and move the suspension with a floor jack.

[neuropel]

Originally Posted by Paul Is the rubbing sound coming from the front tires or rear.......

Rubbing is coming from the rear of the car. It actually sounds like it's in the trunk!

[baz]

todd the easyest thing i can think of is take a wheel off and see where its rubbing
once you know that the answer comes real easy
if its on the inside the wheels need to come out
if its on the outside they need to go in
if its both (when checking both sides it can be outside on 1 side and inside on the other) then you need smaller wheels

[Rionart]

Originally Posted by neuropel Rubbing is coming from the rear of the car. It actually sounds like it's in the trunk!

That's easy then....your trunk monkey needs lubricated....

Remove the rear wheels and have a look for 'witness' marks on the inner arch, if there has been any rubbing you should be able to spot it fairly easily.
If it's minor....a bit of heat and some persuasion may give you the extra clearance. Or you may want to space the rims out by a couple of MM.
HTH, Rob.

[Rionart]

Crikey Baz....great minds and all that....