smparr

I'm trying to replace the rear control arm bushings on my 98 LS. The original shop manual just says to replace the control arms as a unit. I have replacement bushings from RockAuto and cannot find 98 specific control arms. Two questions:

1. I've noticed in the parts book that a 64-67 F85 and a 65-70 88/98 show the same part numbers for all the rear control arms. Has anyone ever tried the Goodmark or Fusick F85 replacement control arms on the B/C body?

2. How difficult is it to press the bushings out of the original control arms? The ones on it are original and pretty stiff and crumbly.

Thanks,
Steve

oldcutlass

Yes they can be replaced, the procedure is the same as an Abody. In simplistic terms, you can burn or drill the rubber out, remove the outer sleeve and then insert a spacer around the new bushing area to keep the control arm from collapsing while hammering the new bushings back in.

Vintage Chief

I just replaced both the upper & lower control arms on my '71 CS convertible w/ new control arms from UMI Performance. I extracted a couple bushings from the control arms as a test run w/ my ball (heavy duty) joint/bushing press & they popped right out after a day of soaking them liberally w/ penetrating fluid. The rear upper control bushings are the buggers to get out since the bushings (left & right side) are attached to the top of the axle differential. Since I had no reason to remove the axle on my vehicle, but needed to remove the bushings in the differential, I opted to purchase & use this bushing extractor/press made by Ridetech specifically for GM A & G body vehicles. It fits right into place without having to remove the axle. It worked well without issues. $40.00. There's a video on YouTube you can look for which demonstrates it's use. GL

https://www.ridetech.com/products/ac...pper-bushings/

joe_padavano

No one stocks complete rear LCAs for the 65-70 full size cars. Yes, the 64-67 A-body LCAs and the 65-70 B/C-body LCAs are the same part number. Yes you can use aftermarket LCAs for a 64-67 A-body. You can also just replace the bushings. Note that while the LCAs are the same, the rear axle and frame width is not. A-body sway bars to not fit the B/C-body cars unless you machine custom spacers.

smparr

I'm not installing a rear sway bar. So the LCAs are the same for A, B, and C body? That makes this easier, at least for lowers. Are the uppers different even though the part number is the same?

joe_padavano

From above:

If the P/Ns are the same, the parts are the same. I actually never bothered to check the uppers, as I was researching the boxed lowers, but now that I look, the parts book shows that all 1966-67 A, B, and C-body cars used the same upper arms also. The 68-70 full size have a different P/N for the uppers, but I suspect that is only due to different hardness of the rubber bushings for NVH tuning. The suspension geometry is the same on all 1965-70 full size Oldsmobiles.

smparr

Thanks for that info. My mechanic I take her to was a little apprehensive about punching out the bushings when the shop manual says to replace the entire rear LCA and UCA. He did a great job with the front ones. I think he just doesn't want to damage the original parts plus he said it's more costly to do the bushings individually. I can find all kinds of A body parts but B/C specific parts are almost impossible.

smparr

Received the Goodmark boxed Rear lower control arms for a 1966 Oldsmobile F85 from RockAuto and they match up visually and part number wise with the stock control arms currently on the 98LS. I haven't had a chance to install them yet. Waiting for the uppers from Fusick to show up. Also for a '66 F85 but match the part numbers of the 98LS in the manual. I looked at the installed ones and they look the same, so keeping my fingers crossed.

smparr

Just received the uppers from Fusick. They never even said they shipped them. They appear to be exactly the same upon visual comparison. I will jack the car up this weekend to put hands on. It's snowing which makes the garage cold so I won't get to it today. Vintage Chief, I saw that tool. I think I might invest in it since B/C bushings are the same as A-body. I tried to find parts to make it but can't find metal pipe or washers in those exact sizes.

Vintage Chief

The tool made short order for both removal and pressing in the bushings without removing the axle. The fit was spot-on.