front digs

[bru21]

I was looking at my leftover bits from my transfer conversion and i can quite easily make a rear disconnect out of it. it would mount to the diff or transfer as a seperate unit and fit in line with the shaft. the biggest broblem is my rear shaft will need to be 300mm shorter, and it is getting short already with the dual transfer kit, 9" from memory shorter.

before i put any more time or thought into it, is there a real benefit to front digs on a challange truck. i can't see it being any weaker than it is as it will use std nissan drivetrain components which do the same thing for front drive. will need a double cardian shaft. i could use the original shift fork and a cable or a pnumatic ram.

cheers bru

[RUFF]

I was looking at my leftover bits from my transfer conversion and i can quite easily make a rear disconnect out of it. it would mount to the diff or transfer as a seperate unit and fit in line with the shaft. the biggest broblem is my rear shaft will need to be 300mm shorter, and it is getting short already with the dual transfer kit, 9" from memory shorter.

before i put any more time or thought into it, is there a real benefit to front digs on a challange truck. i can't see it being any weaker than it is as it will use std nissan drivetrain components which do the same thing for front drive. will need a double cardian shaft. i could use the original shift fork and a cable or a pnumatic ram.

cheers bru

I dont see any reason to need a DC joint after making this. I imagine you are thinking because of the angle. A DC joint wont work at a better angle than 2 Uni joints.

But anyway it will depend on the rules of the event you are competing in. Using it could be looked at as Excessive Wheelspin. But it can still make a turn tighter even without spinning the tyres.

[bru21]

when you say two uni joints do you mean two shafts 3 unis in total or matched angles with 2 unis. i intended to bolt the dog set up directly to the pinion or transfer flange with no uni, and brace it back to the bolting face of the transfer or diff.

if it is in the diff it can rotate to fix alignment and i thought a dc at the transfer would be the go, as the pinion angle would need to be close to zero (pointing at the transfer) as otherwise the dog setup will hang down too low.

cheers bru

[RUFF]

when you say two uni joints do you mean two shafts 3 unis in total or matched angles with 2 unis. i intended to bolt the dog set up directly to the pinion or transfer flange with no uni, and brace it back to the bolting face of the transfer or diff.

if it is in the diff it can rotate to fix alignment and i thought a dc at the transfer would be the go, as the pinion angle would need to be close to zero (pointing at the transfer) as otherwise the dog setup will hang down too low.

cheers bru

One shaft 2 uni's. Match the angles correctly. Dont put it on the diff you would be asking for trouble. One you need to protect it and then its an awfull long pinion if you happen to bend a link or anything your likely to have this set up in the ground or through the tray. DC joints are generaly a bandaid fix for Driveline Vibs.

[hypo]

DC joints are generaly a bandaid fix for Driveline Vibs.

ok then how do u run std unis on the rear of a rig with a short and steep driveline ?? i thought the best thing 2 do wood b point the uni at the tcase so that it also gets the pinion up put of the dirt and use a DC joint at the top 2 fix the angles ???

[bru21]

i guess mounting on the transfer is the go then. i still need to mount a crossmember across the back of the transfer, so that would be a good platform to mount the dog housing to. for driveline vibrations i thought running matched angles caused it to "dog leg" thats what my shaft guy said. whether he has anything to do with 4x4's who knows. so the best bet is to run parallel flanges. to give you an idea my shaft starts about 200 after the chassis brace which runs from left to right

[RUFF]

DC joints are generaly a bandaid fix for Driveline Vibs.

ok then how do u run std unis on the rear of a rig with a short and steep driveline ?? i thought the best thing 2 do wood b point the uni at the tcase so that it also gets the pinion up put of the dirt and use a DC joint at the top 2 fix the angles ???

If its too short and steep your F**ked. You need to re-design your set up. A Normal DC joint will not go through as much of an angle as a pair of Uni Joints.

We are running shafts as short as 450-500mm with 2 Uni Joints and no issues.

[RUFF]

i guess mounting on the transfer is the go then. i still need to mount a crossmember across the back of the transfer, so that would be a good platform to mount the dog housing to. for driveline vibrations i thought running matched angles caused it to "dog leg" thats what my shaft guy said. whether he has anything to do with 4x4's who knows. so the best bet is to run parallel flanges. to give you an idea my shaft starts about 200 after the chassis brace which runs from left to right

Ok the prob your going to have is that your not only short in the shaft but its steap too. And as Ben has pointed out above youve got problems. Usually (in an offroad only vehicle) i would go for a Broken Back method which is pointing the pinion above the Transfer and running the Uni Angles the oposite way to normal but then you will get oiling issues at speeds down the Highway.

If your going to see road miles your prob going to have to go for a Big$$ CV joint like whats offered by Tom Woods Driveshafts in the US- http://www.4xshaft.com/ (look in the middle of this page and click on the BIGELOW Shaft)

[hypo]

DC joints are generaly a bandaid fix for Driveline Vibs.

ok then how do u run std unis on the rear of a rig with a short and steep driveline ?? i thought the best thing 2 do wood b point the uni at the tcase so that it also gets the pinion up put of the dirt and use a DC joint at the top 2 fix the angles ???

If its too short and steep your F**ked. You need to re-design your set up. A Normal DC joint will not go through as much of an angle as a pair of Uni Joints.

We are running shafts as short as 450-500mm with 2 Uni Joints and no issues.

ok but if running 2 unis in a single shaft i thought the angle of each uni had 2 b the same 2 cancel out the angle of the shaft if that makes sence.

if this is the case then its not possible 2 point the pinion up 2 get it out of the dirt if the flanges have 2 b paralell.

or am i not understanding sumthing ?

[RUFF]

DC joints are generaly a bandaid fix for Driveline Vibs.

ok then how do u run std unis on the rear of a rig with a short and steep driveline ?? i thought the best thing 2 do wood b point the uni at the tcase so that it also gets the pinion up put of the dirt and use a DC joint at the top 2 fix the angles ???

If its too short and steep your F**ked. You need to re-design your set up. A Normal DC joint will not go through as much of an angle as a pair of Uni Joints.

We are running shafts as short as 450-500mm with 2 Uni Joints and no issues.

ok but if running 2 unis in a single shaft i thought the angle of each uni had 2 b the same 2 cancel out the angle of the shaft if that makes sence.

if this is the case then its not possible 2 point the pinion up 2 get it out of the dirt if the flanges have 2 b paralell.

or am i not understanding sumthing ?

I think i explaind this in the next reply. You cant point the pinion at the tcase and run only 2 Uni's you would need to go higher than the Transfer and then you end up with pinion bearing oiling issues.

[Bush65]

...ok but if running 2 unis in a single shaft i thought the angle of each uni had 2 b the same 2 cancel out the angle of the shaft if that makes sence...

Yes, but rovers don't do that at the front. They point the pinion up, but rotate the uni yokes out of phase, to cancel the out of phase due to the mis-matched angles.

[redzook]

i always thought "most" DC had a higher operating angle? then a single uni?

[RUFF]

i always thought "most" DC had a higher operating angle? then a single uni?

This generaly depends on the length of the ears of the shaft. A hilux DC joint doesnt go through much of an angle in stock form. The one in the rear of my hilux was maxing out and i didnt realy have that much flex due to the Rover Balljoint. My rear shaft in my buggy is about 550mm long and runs a Hilux Uni at one end(diff) and a 1310 Tom Woods super Flex Uni at the other and i get most of my droop out of a set of 18" Shocks.

[bru21]

thanks i will get a pic if i can. i have a 8" lift too which i will cut back to say 4 or 5". what about the nissan gq tray dc shaft. i have one here. maybe a bit small for the gen 3 and the torque of the dual transfers

[tuf045]

could bru21 possibly reduce the shaft angle buy doing a high pinion conversion the rear axle using a front center with rear hemi and front gears ? assuming he still use's nissan stuff.

[bru21]

no it has a different spline count i think.

i won't do this tconversion for some time, but i like to get all the info 100% so i can just build it when i need to. also so i knew to keep all the gears and shite.

[tuf045]

this front centre into rear will work.
have one the back of the cruiser ( has gq diffs) . what i did was to use a front gq centre remove the hemisphere add airlocker to suit the rear of a gq but with the crownwheel of the front hemifitted to the airlocker centre.
I know that running on the reverse side of the gears is weaker, but have a couple of mates doing this also with v8's in them and havn't had any prob's.

[Wendle]

if you piss the handbrake off the back you can make a rear disconnect REAL short using the output shaft splines and mounting everything off the handbrake mounting pattern. i was gonna do this myself, but i needed all the rear shaft length i could get.