I was having an issue with the rear coils springs allowing the car to hit the bump stops when going over hard bumps and/or some road crossings. 18 months ago I replaced the struts, front and rear, with KYB struts. I still had the bump in the rear issue, so I decided to replace the front and rear coil springs.

RPO codes:
6ZW
7ZW
8NL
9NL

The front coil springs still had the BZW tag on them when I pulled them out.

I ordered and installed Moog 5665 in the rear and 5662 in the front. The front is now ridiculously high. Floor to the bottom of the wheel on the fender is 29.5". I have the GM 1992 Service Manual and it shows the distance from the floor to the bottom of the body @ 32.5" behind the front tire should be 8.031" +- 0.4". I measure 9-3/8" from the floor to the bottom of the GFX.

The height of the Moog's are way to much. I called Moog and they confirmed that 5662 are the ones to use and the guy said he never heard of an issue with these.

Any recommendations on which OEM compatible springs to use would be really helpful.

Thanks

 

have you driven the car since installation? usually they will settle right after driving a short distance.

 

yes. I drove it about 15 miles, no change.

 

How are the rears?
The reason I ask is that I live in CT, and the roads suck.
I would NEVER lower my car, in fact I installed front springs to raise it.
I don't remember the brand, though.
But I am looking to replace the rears, the car has been parked for 20 years.
Anything you can tell me would be appreciated.

Did you make sure the the end coils on the springs were locked into the proper position(s)?

 

OK guys. Which do I choose for daily driving, but more interested in straight line performance rather than corner carving?

 

The rears are good. Height on the body in front of the rear tire is @ 8". Right on spec. It rides good and no longer hits the bump stops. At the center of the rear wheel from the floor to the wheel well is 28".

I'd do the rear again, but not the front.

yes the end coil was indexed into the same position as stock.

 

While I was looking at the MOOG springs on RockAuto, I noticed that the front heavy-duty, constant rate, T/A, A/C, AT have part number 5642. Maybe you received these by mistake, instead of 5662.