Time to lower rear end?

[matt gineo]

I'm planning to have the rear end lowered on my 76 Targa 2.7. How long should it take a shop to do the lowering and bushing replacement not including alignment & corner balance.

Thanks
Matt

[jpnovak]

For me its about a 4-5 hour job to R&R rear spring plates, clean and paint them, replace bushings and reassemble. (more actual time if you count watching paint dry).

This assumes you do not find stuck torsion bars, rust or other items that need attention.

I suggest that you upgrade to adjustable spring plates while you are in there. It will make your CB so much easier.

[Uncle Enzo]

i would also think about repacking/cleaning your CVs. After I dropped mine my CVs took a crap shortly there after.
Also, Im not sure how low you wish to go but I was able to get the desired drop via simply adjusting the eliptical bolt on the plate.

[matt gineo]

Originally Posted by Uncle Enzo

i would also think about repacking/cleaning your CVs. After I dropped mine my CVs took a crap shortly there after.
Also, Im not sure how low you wish to go but I was able to get the desired drop via simply adjusting the eliptical bolt on the plate.

I'm planning to drop to the pre 1976 stock ROW Height. The front has already been lowered. So you're saying if I only drop to factory ROW height it only requires adjusting the eliptical bolt?

I'm pretty sure I want to replace the bushings, there are 63,000 miles on the clock and the car is almost 40 years old.

[Uncle Enzo]

yup. you will get a little drop for sure. However, you will still need to align and balance her after your done. In addition, you will need the skinny wrench sold here to access the nuts behind the plate.

[jpnovak]

The spring plate should be concentric with the spring plate collar. If the rubber bushings are sagging the collar will likely be close to making contact on the top side of the spring plate and a large gap on the bottom. This happens slowly over time.

I have been replacing a lot of these lately for this reason. The rubber is just old, and in most cases, hard. Its a time thing, not mileage.

If you have adjustable spring plates then you can rotate the eccentric bolt. There is not much adjustment and it will depend on how your car is currently setup.

AFIK, the 77 was the first year of adjustable spring plates. I could be wrong. Its easy to look in the wheel well and tell both the type of spring plate and the condition of the bushings.

Don't forget you have to remove the rocker panels to do all this work. That adds time, and in some cases cost to replace the rubber trim strips in the trim. If its old, it might split upon removal.

[uwanna]

If your car came with adjustable spring plates from the factory, be aware, the way they shipped them, they can only be adjusted to raise the car, not lower it!!
Seems pretty stupid I know, but perhaps it had something to do with US height requirements. I know my local Pcar dealer made quite a bit of money back in the day
lowering the rear ends of the insanely high mid '70s-'80s 911 cars. Taking the rear suspension apart versus just adjusting a spring plate is a good bit more expensive!
Most folks adjust the spring plate eccentric to the center position after the first reindexing of the spring plates, so you have adjustment up OR down for corner balancing.

[Bob Kontak]

Originally Posted by matt gineo

So you're saying if I only drop to factory ROW height it only requires adjusting the eliptical bolt?

You can, but the guy on the cover of Bruce Anderson's first performance handbook beat the crap out of me because the plates were not centered. He said that the proper way to do it was through torsion bar indexing.

He also said "Don't listen to a (expletive) thing on them (expletive) forums".

Soooo, maybe take that with a grain of salt as he makes his living from fixing Porsches. Given he worked for Anderson, he probably is not blowing smoke. Let's say at least he knows if he is blowing smoke.

However, I don't know if there is a downside to this. Porsche put the adjustment eccentric there for adjusting.

[redridge]

Originally Posted by Bob Kontak

You can, but the guy on the cover of Bruce Anderson's first performance handbook beat the crap out of me because the plates were not centered. He said that the proper way to do it was through torsion bar indexing.

He also said "Don't listen to a (expletive) thing on them (expletive) forums".

Soooo, maybe take that with a grain of salt as he makes his living from fixing Porsches. Given he worked for Anderson, he probably is not blowing smoke. Let's say at least he knows if he is blowing smoke.

However, I don't know if there is a downside to this. Porsche put the adjustment eccentric there for adjusting.

torsion bars adjustments is the way to go to get both side heights in sync, the eccentric adj are more for "FINE" adjustments when you can't get the torsions adjustments perfect.

[jpnovak]

Exactly, adjusters are for fine tuning. I index torsion bars to have matched angle on each side. They typically need very little adjusting side to side to CB a car.