Hi

2005 Blazer 125k
4wd 2 door / Automatic

Recent work
All brakes parts replaced all the way around except
Front calipers | brake fluid was completely flushed and brakes worked great!! Thanks Captain Hook!

Shocks all OEM

Then took recent road trip - 4500 km towing uhaul trailer, no problems -

While away from home my girlfriend had to slam on the brakes and the whole truck stopped perfectly, locked up and abs worked. She said the back of the truck kinda hopped over. Anyway it still worked fine for another 1300 km back home.

Now, back home on the highway doing 60km-100km you can feel about 1-2 seconds of vibration in the truck... it's not in steering wheel

I can hear a screech too like a grinding brake but it doesn't happen at the time of the vibration which is felt in the seat. Sounds like its from rear of truck.

So to recap, I'm driving down highway... All is fine.

then vibration which appears to only happen when on the gas, you feel it in your seat, it appears to come from rear. doesn't feel safe, feels as if it slows the truck a bit. then it goes away for 7 seconds then comes back.

So I took it to shop and they only had time to rebalance the tires, 3 out of 4 needed done.

Brakes still work great.

I'm at a loss as to what would cause this 1-2 second vibration which is about 5 "what ever the heck" bumps. there is no way it's the "ROAD"

I thought:

loose caliper bolts?
u joint bolts?
lose shock bolts
Something with engine?

Any ideas?

 

id call rear calipers

 

Thanks!

The caliper themselves or the bolts that hold it down?
Damn things were brand new!

 

just an update. took off rear tires

caliper bolts were slightly loose but nothing major.
e-brake test shows ebrake doesn't hold but the cable does retract properly. no problems with rotor that is new . shocks at top and bottom aren't loose

exhaust is fine.
u joint at rear and front of driveshaft is good. no play

took remaining front tires off front , all looks good no major damage all caliper bolts fine

no major drag on brakes

shocks on front seem fine
no major wobble or anything around area

I found tranny dipstick not locked into place but god that wouldn't do it.

Damn too bad I didn't find anything!!!

Hate to think it's tranny related!

Tomorrow I go for ride with mechanic at 10am and hopefully I can reproduce it.

Going for ride to gym now but don't think my speeds will be high enough to get it to do it.

I'll keep everyone posted...

 

omg get this

radial run out on front tires. I guess they put it up on hoist and ran it in 4x4 and could visual see the run out.

when the balanced the tires and rotated it they must of moved the tire from the rear to the front and that is why shake migrated to front.

insane, there is only 39 k on these tires, 26 months old.

wonder if old shop will warranty the good year wrl sltarmr xl owl tl tires

 

please close thread, after the next highway trip the tranny still vibrates at 80 km/hr in OD and I can hear metal on metal every now and then.

I took tranny expert with me and he told me it is definitely not my brakes and he took the scan tool with him. The converter locks up and then shutter happens shortly there after and as well as grind.

I reproduced the problem twice and he heard both. he said it's torque converter.

will repost my next question in other forum
'