Lengthening front driveshaft M1008

[twomorestrokes]

Before jumping on me, I did a search but didn't find the answer.

I've installed 4" springs and zero rates in the front, moving the axle forward 1". Any ideas on how much I'll need to add to the front drive shaft length?

 

[sandman7655]

None.There is plenty of length in the shaft for that.

 

[Cucvnut]

No you will need to lengthen it. I can measure mine if you want to let you know what i ended up at.

 

[sandman7655]

ok ,well i got 8 inches of lift on mine and didnt have to lenghten it.if you want it to be in stock dimension but other wise you shouldnt have to lenghten it.

 

[Cucvnut]

He moved his axle forward you need to lengthen the front drive shaft, I had to do the same thing.

 

[Sharecropper]

I raised my M1028 exactly as you did, with 4" front springs and Zero-Rates with the front axle moved forward 1 inch.

I can guarantee you that you will need a longer front shaft.

I got mine from Tom Woods Custom Drive Shafts in Ogden, UT Tom Wood's Custom Drive Shafts - Tom Woods Custom Drive Shafts Custom Driveshafts Specialist . Give them a call and they will walk you through how to measure.

Hope this helps.

 

[dstang97]

they do make a spacer that bolts on to the flange to extend it. You could also go to the junk yard and find another one that is longer. I think a 89-98 drive shaft is longer.

 

[sandman7655]

It should be a standard chevy drive shaft and i cant see how it needs to be longer with such a small amount of lift .even with moving it forward an inch.I have been lifting trucks for 20 years and just dont see it.I could be wrong.

 

[1ton cucv k5 turbo]

i would run what you have... worse thing that will happen... if offroading and it pops out... limp back to level ground and put it back together.. and than.. find your way to a shop to retube it longer, an inch or 2"...

look at my avatar... thats me pulling what was left of mine out... and she backed down off of there in 2 wheel drive... spend the rest of the day on easy trails... the following week.. had it fixed.. and my spare done as well, and will keep it strapped in the back.. that way.. im good to go, if i break another....

 

[twomorestrokes]

Silly question but I'm somewhat new to lifts. How do I determine if it needs lengthening? I left it hooked up when I swapped parts and it's still on but the splines are inside the rubber boot.

 

[ODdave]

i would run what you have... worse thing that will happen... if offroading and it pops out... limp back to level ground and put it back together.. and than.. find your way to a shop to retube it longer, an inch or 2"...

look at my avatar... thats me pulling what was left of mine out... and she backed down off of there in 2 wheel drive... spend the rest of the day on easy trails... the following week.. had it fixed.. and my spare done as well, and will keep it strapped in the back.. that way.. im good to go, if i break another....

..........


Yea, then it flys around and hits other stuff (oilpan) or jams in something and breaks the trans or t-case..........

 

[1ton cucv k5 turbo]

..........


Yea, then it flys around and hits other stuff (oilpan) or jams in something and breaks the trans or t-case..........

that is possible,.... but the 3 times ive broken one.... i wasnt going fast enough for it to do that type of damage.... and knew to shut it down....

 

[twomorestrokes]

Well I unhooked the shaft at the front and pulled the boot back and looks like 4-5" of spline engagement. Whaddya think?

 

[Cucvnut]

You dont want any spline showing on a drive shaft.

 

[sandman7655]

You dont want any spline showing on a drive shaft.

Wrong.if there is no spline showing it cant compress with the suspension and you will bend or damage something.put the lift on the truck then look at the shaft with suspension aat full droop.if the shaft is still together you will be fine.

 

[twomorestrokes]

I went underneath and actually measured. There is 4" of total splined length, and 3" of that is engaged into the front section at normal ride height with the 5" of lift and axle forward 1". I'll see what happens at full droop and go from there. Thanks!

 

[Cucvnut]

Wrong.if there is no spline showing it cant compress with the suspension and you will bend or damage something.put the lift on the truck then look at the shaft with suspension aat full droop.if the shaft is still together you will be fine.

not true. if you have it built with enough spline inside and its long enough you don't need any spline showing when it compresses. Both my my d shafts do not have any spline showing and they compress just fine.

 

[sandman7655]

ok ,,we can go back and forth on this.if no spline showing and the shaft cant slide any further in then it will bind.but i am willing to bet that the shaft doesnt need to be longer to work fine.i have 8 inches of lift and mine is borderline and only needs about 1.5 inches to be worry free.but to each his own.

 

[1ton cucv k5 turbo]

I had picked up 3 Front shafts and had retubed and with 8" spline... both front and rear show about 2-2 1/2" with 4" lift.. on recenterd axles... entire suspension was reworked with 52" Springs all the way around... with Axles dead centered on wheel wells... Because of my doubler as well, I got to set it up that both front and rear will interchange.. and the 3rd is a spare for either, in the event i break another one... ( hence the avatar pic...)

i have to concur with Sandman.... you have to have some spline showing at ride height... if not.. your outting too much pressure at yoke and at transfercae,, which in turn stresses the mounts and entire Driveline... thats why I went with 8" slips.. as so i wont lose strength at fully dropped.... Even at Stock height the front shaft shows a little for compression....

my advise... leave Front shaft out... pull measurement.. yoke to yoke, then position truck iin a ditch or on something to articulate the suspension.. and pull another... Ideally you will want 3 measurements... compressed, normal ride height, and fully Dropped... take those measurements, and see if your drive shaft can match it... that way, you will know for sure if you will end up having to modify yours... and save you from learning the hard expensive way...

Thats what i had to do...

 

[twomorestrokes]

Everything's back together and here's what I see. 1" spline showing at normal ride height, which means 3" engaged. I can't take any measurements during articulation yet as I have not installed my brake hoses. I would imagine the real test would be with the LF fully compressed with the RF at full droop. Hopefully I can check that soon.