I recently had FRPP 4.10's installed, I live about 50 miles from the shop that put them in. On the way home i had no issues and was cruising between 50 and 70. I let the car sit and cool down that night. The next day I took it out in the morning and drove it around for awhile not jumping on it just driving around and then let it cool down again. That night I took it back out and decided to get on it a little bit, and once i hit about 60+ the car started to vibrate so i got off of it and once i got below 60 it stopped. I stepped on it again from about 40 and as soon as i hit 60+ the same thing again. Any ideas on whats causing this to happen?

 

Sounds to me like an issue with the driveshaft.

 

Atleast he doesnt have a driveshaft in his sig, so I highly doubt its the driveshaft since the stock 2 piece absorbs ALOT of vibrations. For me its just a bad instalation of the gears.

 

Could be anything, bring it back and have them look at it. Drive shafts are a very common source of vibration, maybe it wasn't torqued properly etc.

 

Take it back to them where you had it installed and have them ride in it with you.

 

how much did you pay, what type of shop was it, how many 8.8 ford rear ends have they done.....need more info please

 

I took it to Evolution performance, the total came out to around $700.

 

Wow EVO....hmm....i would take it back to them then.....they should be able to tell you exaclty what is up and get it fixed

 

I'm thinking thats gonna be my best bet. Now if the weather here in PA would be halfway decent i could get it down there.