Driveshaft problem with flip kit - The 1947 - Present Chevrolet & GMC Truck Message Board Network

texas56 · 07-30-2009, 07:02 PM

Im sure I saw this somewhere on here but cant seem to find it. The driveshaft is all the way into the trans and is too far. What do I have wrong? It is a 86 Short Bed.

flamingbig10 · 07-30-2009, 07:29 PM

you either have a the leafsprings fliped around or the spring perches need be fliped around

jasonblinn · 07-31-2009, 10:28 AM

i had the same problem with my 86 short box,i went with a shorter driveshaft,1 off a 4x4 long box,around the same year.but now since i did that i have a bad vibration

Turbo85GMC · 07-31-2009, 11:23 AM

The holes in the new perches (in the flip kit) go towards the front. That will essentially shift the axle back slightly. That is necessary because of the geometry change.

jasonblinn · 07-31-2009, 11:40 AM

i cut my perches and switched them over,maybe that wasnt the right thing to do??

bigarmzz · 07-31-2009, 12:07 PM

Quote:

Originally Posted by jasonblinn

i cut my perches and switched them over,maybe that wasnt the right thing to do??

summit sells some pinion shims that would work for ya...they go in between the leaf and the perch to correct the angle of the rear end/drive shaft...there pretty cheap too, maybe $20 total or so

**nlped** · 07-31-2009, 03:04 PM

If you just moved your perches to the bottom of the axle tube you need to drill a 3/4" diameter hole 1" (center to center) forward of the existing locator hole. Then just use that hole for the assembly bolt on the spring. This will allow the correct offset for the change in driveline geometry. Basically the same concept as how the flip kit bracket has the offset hole. I am going to have to do the same thing.

Cheers,

Ed

**lolife99** · 07-31-2009, 04:33 PM

Quote:

Originally Posted by jasonblinn

i cut my perches and switched them over,maybe that wasnt the right thing to do??

How did you measure your pinion angle?
Sound like you need to relocate the axle rearward or shorten your driveshaft. Either way you need to check your pinion angle to verify it's correct.

3r!c84 · 07-31-2009, 04:49 PM

[QUOTE=lolife99;3440639]How did you measure your pinion angle?
with a angle finder lol

jasonblinn · 07-31-2009, 05:01 PM

how do i check my pinion angle?i just didnt it by eye.looks right but probably isnt.i asked a few people around and i get different answers.

**nlped** · 07-31-2009, 07:12 PM

You need an angle finder to set the pinion angle to the correct angle. I bought one at Lowes in the tool "barn". It's magnetic, so I just stuck it to the pinion flange and put the rearend and new perches in place and rotated it until is was at 3 degrees which is what the stock angle was at and spot welded the perches then pulled it back apart and welded everything up. O BTW, made sure the truck was level left to right and front to back to confirm the angle was correct across the board.

jasonblinn · 07-31-2009, 07:24 PM

man i wish i wouldve known about this site sooner..lol..it wouldve been done right the 1st time.what about with the truck up in the air on a hoist,it wont change the angle?

**nlped** · 07-31-2009, 08:07 PM

On a hoist, a lift or a drive on rack (like an alignment rack)? The suspension needs to be "loaded" to get the correct angle, because as the suspension moves through the range of motion the angle will change slightly due to the way a leaf spring suspension articulates. That's fancy talk for, it needs to be level and the suspension needs to have weight on it to get the angle right.

07-30-2009, 07:02 PM	#1
texas56 Registered User Join Date: Jun 2009 Location: Dickinson Texas Posts: 286	Driveshaft problem with flip kit Im sure I saw this somewhere on here but cant seem to find it. The driveshaft is all the way into the trans and is too far. What do I have wrong? It is a 86 Short Bed. __________________ 1955 First Series Thriftmaster Blown 355 TH400, S10 Chassis,narrowed 9 Inch rear, air ride, 4 wheel disc brakes, 20s and 22s,

07-30-2009, 07:29 PM	#2
flamingbig10 6.0 powered square Join Date: Feb 2008 Location: Mesquite texas Posts: 3,459	Re: Driveshaft problem with flip kit you either have a the leafsprings fliped around or the spring perches need be fliped around __________________ Aaron 1980 c-10 short bed lowered, cammed 6.0, 4l80e 3600 stall, smp tune, wilwoods, and flames best time so far best et 7.86 @87 on motor 7.57 90 on a 75 shot Build http://67-72chevytrucks.com/vboard/s...d.php?t=283326 Last edited by flamingbig10; 07-30-2009 at 07:29 PM.

07-31-2009, 10:28 AM	#3
jasonblinn Registered User Join Date: Jun 2009 Location: nova scotia Posts: 14	Re: Driveshaft problem with flip kit i had the same problem with my 86 short box,i went with a shorter driveshaft,1 off a 4x4 long box,around the same year.but now since i did that i have a bad vibration

07-31-2009, 11:23 AM	#4
Turbo85GMC Registered User Join Date: Apr 2005 Location: Medford, MA Posts: 307	Re: Driveshaft problem with flip kit The holes in the new perches (in the flip kit) go towards the front. That will essentially shift the axle back slightly. That is necessary because of the geometry change. __________________ '85 GMC 1500 "Friends don't let friends drive stock!"

07-31-2009, 11:40 AM	#5
jasonblinn Registered User Join Date: Jun 2009 Location: nova scotia Posts: 14	Re: Driveshaft problem with flip kit i cut my perches and switched them over,maybe that wasnt the right thing to do??

07-31-2009, 03:04 PM	#7
nlped Senior Member Join Date: Jul 2009 Location: Hayden, Al. Posts: 4,148	Re: Driveshaft problem with flip kit If you just moved your perches to the bottom of the axle tube you need to drill a 3/4" diameter hole 1" (center to center) forward of the existing locator hole. Then just use that hole for the assembly bolt on the spring. This will allow the correct offset for the change in driveline geometry. Basically the same concept as how the flip kit bracket has the offset hole. I am going to have to do the same thing. Cheers, Ed __________________ Carter 1968 Chevy SWB Fleet... Walt 1963-1/2 Ford Falcon Futura...Martha Last edited by nlped; 07-31-2009 at 03:06 PM.

07-31-2009, 04:49 PM	#9
3r!c84 Badass Join Date: Jan 2009 Location: lox. fl Posts: 4,586	Re: Driveshaft problem with flip kit [QUOTE=lolife99;3440639]How did you measure your pinion angle? with a angle finder lol __________________ Think outside the box? -84c10 (1stcar)→My Build← -00 Saturn 5spd drop a gear and disappear! 1/4:13:90

07-31-2009, 05:01 PM	#10
jasonblinn Registered User Join Date: Jun 2009 Location: nova scotia Posts: 14	Re: Driveshaft problem with flip kit how do i check my pinion angle?i just didnt it by eye.looks right but probably isnt.i asked a few people around and i get different answers.

07-31-2009, 07:12 PM	#11
nlped Senior Member Join Date: Jul 2009 Location: Hayden, Al. Posts: 4,148	Re: Driveshaft problem with flip kit You need an angle finder to set the pinion angle to the correct angle. I bought one at Lowes in the tool "barn". It's magnetic, so I just stuck it to the pinion flange and put the rearend and new perches in place and rotated it until is was at 3 degrees which is what the stock angle was at and spot welded the perches then pulled it back apart and welded everything up. O BTW, made sure the truck was level left to right and front to back to confirm the angle was correct across the board. __________________ Carter 1968 Chevy SWB Fleet... Walt 1963-1/2 Ford Falcon Futura...Martha Last edited by nlped; 07-31-2009 at 07:14 PM. Reason: illiteracy

07-31-2009, 07:24 PM	#12
jasonblinn Registered User Join Date: Jun 2009 Location: nova scotia Posts: 14	Re: Driveshaft problem with flip kit man i wish i wouldve known about this site sooner..lol..it wouldve been done right the 1st time.what about with the truck up in the air on a hoist,it wont change the angle? Last edited by jasonblinn; 07-31-2009 at 07:27 PM.

07-31-2009, 08:07 PM	#13
nlped Senior Member Join Date: Jul 2009 Location: Hayden, Al. Posts: 4,148	Re: Driveshaft problem with flip kit On a hoist, a lift or a drive on rack (like an alignment rack)? The suspension needs to be "loaded" to get the correct angle, because as the suspension moves through the range of motion the angle will change slightly due to the way a leaf spring suspension articulates. That's fancy talk for, it needs to be level and the suspension needs to have weight on it to get the angle right. __________________ Carter 1968 Chevy SWB Fleet... Walt 1963-1/2 Ford Falcon Futura...Martha



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