Vibration with regearing to 488 - Ford Truck Enthusiasts Forums

Go Back   Ford Truck Enthusiasts Forums > Misc. > Offroad & 4x4
Log In 

Offroad & 4x4 SPONSORED BY:

Vibration with regearing to 488

LinkBack Thread Tools Search this Thread
Old 06-19-2014, 09:38 PM
Black Ford XLT's Avatar
Black Ford XLT Black Ford XLT is offline
Elder User
Join Date: Aug 2002
Location: Swansea SC
Posts: 843
Black Ford XLT is starting off with a positive reputation.
Vibration with regearing to 488

Seems after re gearing my 1992 ford bronco a vibration is occurring at speeds 40-50 mph and on and off the gas at any speeds. With stock gears and the 6 inch skyjacker lift there was no vibration, it happened with re gearing .Havent had time to check u joints , but was seeking opinions of others who have did a 6 inch lift and re geared if they had similar problems . Shop who re geared noticed the vibration and took it to a 4 x4 shop, in which the owner said the pumpkin would have to be realigned(cutting welding etc) opinions Please thanks TR
1985 F-150,4x4

1992 Bronco-XLT
Reply With Quote
Old 06-19-2014, 10:21 PM
Nothing Special's Avatar
Nothing Special Nothing Special is online now
Posting Guru
Join Date: Feb 2013
Location: Roseville, MN
Posts: 2,268
Nothing Special has a very good reputation on FTE.Nothing Special has a very good reputation on FTE.Nothing Special has a very good reputation on FTE.Nothing Special has a very good reputation on FTE.
With 4.88 gears your driveshaft will be spinning faster than before. That would make a previously existing vibration worse. If it previously was barely (or maybe not even) noticeable, "worse" could be what you're feeling now.

Lifts will usually mess up U-joint angles which will cause vibrations. If you don't have a double Cardan (CV) joint you ideally want the angles at each end of the shaft to be the same, so you want your pinion parallel to your output shaft. If you do have a double Cardan joint then you want the pinion turned up so it's almost pointing straight up the driveshaft (usuallu about 1 degree low is preferred).

If it's the front axle, then yes, a lot of work is needed to change angles. But then again, if it's the front axle you might be OK just leaving it in 2WD and unlocking the hubs if your fourwheeling is at low enough speeds to keep the vibration down (that's my solution with a 6" lift in my '71 Bronco).

If it's the rear axle then all you need to cut and weld is the spring perches (and maybe the shock mounts). I did that on the rear of mine. wasn't a big deal.
'97 F-250HD 4WD Crew Cab, 460, E4OD, 4.10:1
'71 Bronco, 302, NV3550 5 spd, Atlas 4.3:1, 4.10:1, Detroit rear, 33" BFG AT
My toys:
Reply With Quote
Old 06-21-2014, 01:51 AM
totalloser totalloser is offline
Senior User
Join Date: Jun 2014
Posts: 202
totalloser is starting off with a positive reputation.
Other options to explore might be adding tapered shims or shackle mods to aim the rear diff, and possibly "clocking" the transfer case for better front driveshaft angles.

Another note is that vibrations in that speed range are typical for out of balance or out of round tires. Which I'm guessing may have gone on to match the lift.

Make sure the driveshaft is clocked properly if it's a multipiece. Improperly clocked u-joints will destroy ALL KINDS of things. I doubt this is the issue since with a 6" lift you would probably no get the truck around the block with the d/s clocked wrong, but some driveshafts can be assembled half a tooth off due to an odd spline count, which will be much less severe than the 90 degree misclock that people err with now and then.
Reply With Quote

Similar Threads
Thread Thread Starter Forum Replies Last Post
2003 Excursion - Vibration (lengthy) majestek12 Excursion - King of SUVs 27 09-16-2015 03:06 PM
Vibration heard during acceleration ox1969 1987 - 1996 F150 & Larger F-Series Trucks 5 06-15-2015 04:29 PM
Vibration after regearing to 488 Black Ford XLT 1978 - 1996 Big Bronco 2 06-24-2014 05:32 PM
66 f100 4x4 vibration danno75 1961 - 1966 F-100 & Larger F-Series Trucks 1 04-12-2014 02:20 PM
Update on driveline vibrations dave91gt Excursion - King of SUVs 43 12-30-2013 09:34 PM

Go Back   Ford Truck Enthusiasts Forums > Misc. > Offroad & 4x4

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

All times are GMT -5. The time now is 09:20 AM.


Advertising - Terms of Use - Privacy Statement - Terms of Service - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup