Vibrations!!!!

[bigbadchev84]

I have a vibration that is driving me nuts! I am running a 72 blazer 44/60 axles 4.56 gears 350/465/205 8" suspension lift 35x15x16 boggers.

Here is the deal. Ever since I put this thing together it has had a bad vibration from 15miles an hour and below coming to a stop especially, it rattles the whole truck pretty bad. I tore my 84' shortbox apart to build the blazer, I had the same vibes but it was nowhere near this bad, just a little vibration coming to a stop, nothing compared to the blazer.

I chalked all this up to bad driveline angles, I just bought a High angle driveline cv shaft and rotated the axle perches today, the pinion is 1* below the driveline angle to compensate for axle wrap. It helped a little but nothing to what I hoped.

I was at my brothers and was having him pop the clutch to check axlewrap There is a Clunking like metal on metal clunk coming from the bellhousing/transmission. It drives fine though higher rpms and everything, just vibrates coming to a stop.

 

[Hogback Fabrication]

I have a vibration that is driving me nuts! I am running a 72 blazer 44/60 axles 4.56 gears 350/465/205 8" suspension lift 35x15x16 boggers.

Here is the deal. Ever since I put this thing together it has had a bad vibration from 15miles an hour and below coming to a stop especially, it rattles the whole truck pretty bad. I tore my 84' shortbox apart to build the blazer, I had the same vibes but it was nowhere near this bad, just a little vibration coming to a stop, nothing compared to the blazer.

I chalked all this up to bad driveline angles, I just bought a High angle driveline cv shaft and rotated the axle perches today, the pinion is 1* below the driveline angle to compensate for axle wrap. It helped a little but nothing to what I hoped.

I was at my brothers and was having him pop the clutch to check axlewrap There is a Clunking like metal on metal clunk coming from the bellhousing/transmission. It drives fine though higher rpms and everything, just vibrates coming to a stop.

It could be the coupler sleeve between the 465 and 205. Its a 10 spline setup and notorious for wearing out and causing vibration.

 

[bigbadchev84]

Just had it apart, the sleeve is in awesome shape, I forgot to mention too that in my shortbox i had a 465/208 setup, I installed that in the blazer but it was to long of a set-up, so i had to get the 465/205 i just un-bolted the bellhousing and slid the new 465 in

 

[DPI]

Did you happen to check the pilot bushing?

 

[Hogback Fabrication]

All the joints in the steering and front axle are tight and in good shape?

What about pinion bearings? Is there any play side to side or in and out at the yoke?

Is there any play at the output of the 205?

 

[bigbadchev84]

no I didnt, It has been longer than I can remember since i have had the bellhousing removed from the engine, could a bad bushing be causing this?

 

[Hogback Fabrication]

no I didnt, It has been longer than I can remember since i have had the bellhousing removed from the engine, could a bad bushing be causing this?

IMO, if the problem is up there, its more likely that the trans to bellhousing bolts are loose.

 

[bigbadchev84]

All the joints in the steering and front axle are tight and in good shape?

What about pinion bearings? Is there any play side to side or in and out at the yoke?

Is there any play at the output of the 205?

the front axle checks out good, pinion bearings are good too, there is about 1/16" up/down movement in the output on the 205, transmission shop said that was normal?

 

[bigbadchev84]

IMO, if the problem is up there, its more likely that the trans to bellhousing bolts are loose.

The bellhousing is tight, I locktight those bolts when i install them, i crawled underneath while he was popping the clutch, the bellhousing is still tight, but i can feel the klunk through the bellhousing and transmission

 

[Hogback Fabrication]

There shouldn't be any kind of "clunk" up there. Could be clutch, flywheel, transmission, etc.

 

[bigbadchev84]

I was just talking to my brother and he described it "its like it jumps and clunks at the same time" it is totally in the bellhousing area. I guess I will be tearing into it soon. The thing is it drive fine at hight rpms, it is just when slowing down
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[bigbadchev84]

can someone please tell me for sure if a pilot bushing could be the cause of the vibrations? As I said before it totally acts fine until im 15miles an hour and below slowing down, even with the clutch pushed in.

 

[Hogback Fabrication]

can someone please tell me for sure if a pilot bushing could be the cause of the vibrations? As I said before it totally acts fine until im 15miles an hour and below slowing down, even with the clutch pushed in.

I don't think a pilot bushing could cause that.

 

[DPI]

The pilot bushing was just something I threw out there. It keeps the tranny input shaft centered which includes the clutch plate. I wouldn't completely rule it out, but I doubt it could be causing all the issues.

Does the vibration continue with the clutch peddle pushed in? Does it do it in nuetral or in all the gears? Is there an inspection cover? I would pull it if there is and take a look for pieces of clucth material or anything weird...

 

[chulisohombre]

I don't think a pilot bushing could cause that.

front input shaft bearing maybe.have to pull tranny and look for slop on input shaft.i think mine is going out also.has the same problem,but my bellhousing was cracked 4 i dont know how long before i figured out the problem.

 

[bigbadchev84]

Well I hope i Just solved my problems, Just went and bought 90 blazer with an injected 350 and 350/205 combo that was swapped in. will be parting it out in a couple weeks.