Picked up my Blazer today....New Gears

[72 Blaze]

Ok I pickeded up my 72 from the shop today. I had the 4.10s installed. Let me say first I'm happy. I can tell a big difference from the 3.07s that were stuffed in the pumpkin from the factory. But I have some questions. I have always had a small vibration around 30-40mph.. I installed a transfer case drop down kit... It fixed the problem but the big dizzy I was running was hitting the firewall.. I cut the drop down kit in half and then went to a smaller dizzy. One with the coil not in the cap. That fixed the firewall problem. But the vibration was back.. Not bad just a little bit.. I have been driving that way for a year now.I'm ticky... As I was driving the blaze home to day I felt like the vibration had gotten worse.. The guy told me when I picked it up he did feel a small vibration under acceleration.. To me it feels bad (worse than before). not all the time just around thoes speeds.. What could have been done to cause this or make it worse.. I do need to get my tires rotated and ballanced..... BUt I dropped A @#%&*! lLOAD of money into this ol blaze only to have a bad vibe!! Its only a 4" lift with 35's!

 

[bot0611]

Is the d-shaft in good shape? i get vibes at around 50-60 MPH and i suspect the t-case is the problem.... are the wheels straight??? is the rear axle straight? it could be anything in the driving gear or anything in the body..

 

[K5dreamer]

definately a driveline vibration. first things first, get the tires balanced. just to rule them out, but if its under accelleration i dont think thats your issue. when was the last time you had your U-joints replaced? or serviced? also check your mounting bolts to the t-case or pumpkins. my front driveshaft was coming off, two loose bolts out of four holding it on, i had a wicked vibration till i locked it down with four new bolts.

 

[72 Blaze]

I'm going to take a good look at it. Every thing under the rig is pretty much new. I'm just trying to figure out why regearing made it worse...

 

[sweetk30]

blazers with lift need c/v head drive shaft a lot more than trucks do cause the angles .

check for play in joints and slop in the splines for the slip.

she needs to be good and tight or it will wobble around and vibe.

dont forget the shaft is spinning faster now from the gear drop. might be balence prob .

 

[scottsdale86]

Ok I pickeded up my 72 from the shop today. I had the 4.10s installed. Let me say first I'm happy. I can tell a big difference from the 3.07s that were stuffed in the pumpkin from the factory. But I have some questions. I have always had a small vibration around 30-40mph.. I installed a transfer case drop down kit... It fixed the problem but the big dizzy I was running was hitting the firewall.. I cut the drop down kit in half and then went to a smaller dizzy. One with the coil not in the cap. That fixed the firewall problem. But the vibration was back.. Not bad just a little bit.. I have been driving that way for a year now.I'm ticky... As I was driving the blaze home to day I felt like the vibration had gotten worse.. The guy told me when I picked it up he did feel a small vibration under acceleration.. To me it feels bad (worse than before). not all the time just around thoes speeds.. What could have been done to cause this or make it worse.. I do need to get my tires rotated and ballanced..... BUt I dropped A @#%&*! lLOAD of money into this ol blaze only to have a bad vibe!! Its only a 4" lift with 35's!

I cant help but that is a nice blazer!! Kudos to you!!

 

[doubletrouble]

Thats a very nice blazer, I bet there is a huge difference with the new gears.

 

[72blazerguy]

Sweet ride

I'm just trying to figure out why regearing made it worse...

When I swapped from 3.07 to 4.56, I picked up a wicked vibration. Thought the gears were screwed for awhile. Ended up putting a CV drive shaft in when I installed my doubler, fixed the vibration (with 6" shorter drive shaft).

 

[72 Blaze]

Thanks for all the input guys. I think its in the drive shaft too! Where is the best place to order one? I'm going to drive it for a couple of days first, I just need to know where to get one! Cheap! I'm broke! Again thanks for all the support, and compliments!

 

[72blazerguy]

Thanks for all the input guys. I think its in the drive shaft too! Where is the best place to order one? I'm going to drive it for a couple of days first, I just need to know where to get one! Cheap! I'm broke! Again thanks for all the support, and compliments!

Unfortunately, cheap and CV drive shafts don't go together. A local drive line shop can rebuild yours with a CV (cheapest option).

Both of these are popular here (spendy)...

http://www.highangledriveline.com/

http://www.4xshaft.com/index.html

 

[72 Blaze]

Ha! Thats what I was afraid of!

 

[sweetk30]

if you wana keep the money local i have heard nothin but good stuff with olivers in nc http://oliverscustomdriveshaft.com/

or if you want the best around here we use highangle driveline http://www.highangledriveline.com/

i meet the olivers guys face to face at here shop. nice bunch of guys and real good prices when i was shopin around

 

[blazinzuk]

I am a big fan of using local shops for driveline stuff, unless its something weird. My local shop has been able to handle everything from long spline stuff to conversions to high angle cvs.

More than likely in the driveline and the reason it got worse (as stated before) is because your shaft is spinning faster now

 

[sweetk30]

ya you would be amazed at what a 1/2 oz. of balence out will do.

 

[DieselWarrior]

Maybe not as common, but here too:
http://www.driveshaftsuperstore.com/CUSTOM_Chevy_Drive_Shafts.htm
Look for:
"Blazer or GMC Slip with CV Drive Shaft Standard Angle 1310 1/2 ton -- $275 for 6 inch lifts"

This is the one I will be getting, I hope!

 

[Big Ray]

sweet rig

 

[Blue85]

Unfortunately, there is no cure for this vibration. But since you seem like a nice guy, I'm willing to take the vehicle off your hands for, say... 1.5x current scrap?


Now seriously, the CV joint is the silver bullet. If the money isn't a big deal, go right to a 1-ton CV for long, vibration free running. But you might not have to spend that coin. Go get an angle finder and measure the pinion angle and the T-case output angle. These should match and will tell you what needs adjustment. Make sure the slip is tight and not wiggling around. With correct angles it may be acceptable.