D300 guru's

[Mr DJ]

Have fully rebuilt my D300 which is behind a 5.0 + AOD tranny.
D300 has clocking ring upgraded input shaft, F&R outputs + 4:1 reduction.
It has a vibration in the rear drive stick (twin sticks) during coasting (in gear with no load on box).
During acceleration & deceleration it is fine.
Uni's & drive shafts are new.
I'm guessing I got the shimming of the input or output shaft slightly wrong so have to pull it out and check them.

Just hoping someone may have had this issue before and may be able to say exactly where to check first before ripping it all appart.

[DamTriton]

Given the nature of the vibration it could also be due to your digg pinion angle not being set up right (not having equal angles on the UJ's). No vibes under load indicates means you need to tilt the diff back (ie fat edge of any wedges put in place to the front of the vehicle). If the vehicle had also had a lift while all the work was being done this would be the most likely culprit.

Easy way to test the theory is to put the vehicle into reverse. If it vibrates under load and is vibe free under coasting then it is definitely the diff end of the driveshaft.

[Mr DJ]

Appologies for not checking your reply Damkia , too much going on.

Vibes are only under coasting, none under load (acceleration or deceleration), has coils so bit more of a PITA to rotate pinion.
Was fitted as part of a complete drive line conversion which has ended up making the rear drive shaft longer making uni angles better than before.

Will check output & pinion flange angle, tho pretty sure they are ok.

[Wooders]

Sorry mate - sounds like driveline angles are causing the vibs.

[Mr DJ]

OK, have checked rear uni's and are good, gearbox/transfer mount is good, control arm bushes are good.
Did find that there was the slightest bit of movement in the transfer output flange, so tightened the centre bolt (less than 1/8 turn) and is now very tight. Will see how this goes tomorrow with a run out on the highway.

Transfer rear Output flange (mating face)- 0 deg.
Drive shaft - 13 deg.
Diff Pinion flange (mating face) - up 1.5 deg.

These numbers seem to be ok to me with a working angle of 6.5 deg. at tranfer and 5.75 deg. at pinion, if I have worked it out correctly.

EDIT: got it wrong - working angle at transfer 13 deg. and pinion 11.5 deg. and they are less than 4 deg. difference so all should be good.

From here - http://www.vibratesoftware.com/html_hel ... tm#Measure" onclick="window.open(this.href);return false;

[Mr DJ]

Still there but not as bad .... any other suggestions ??

[Wooders]

Keep in mind the pinion will climb a few degrees, thus reducing the operating angle at the pinion end and incrasing the difference.
I'd prefer the pinion to be about 1deg lower than the t/case.

[Mr DJ]

If you mean during articulation, won't it drop a few degrees as the top arms are shorter than the lowers on a 4 link + panhard ?

Have run it with the front shaft only in and vibes are gone, so thinking it must be the rear shaft. Has been suggested I will have to run a Double Cardin joint to get rid of the vibes.

[udlman]

Are the rear driveshaft Uni's out of allignment?

[Mr DJ]

No, they are in phase.
Have had the shaft re-balanced by the makers Hardie Spicer and although there is less vibration, it is still there.
The slip joint does have a tiny bit of movement but was told this would not cause the problem by Hardie Spicer ..... not sure I agree with them tho.

[Wooders]

If you mean during articulation, won't it drop a few degrees as the top arms are shorter than the lowers on a 4 link + panhard ?

Have run it with the front shaft only in and vibes are gone, so thinking it must be the rear shaft. Has been suggested I will have to run a Double Cardin joint to get rid of the vibes.

No I mean during acceleration/deceleration the pinion angle changes.
A double cardan joint will certainly run smoother (assuming it's correctly setup). However is more expensive.
what's the length of your tail shaft.
How much lift have you got? 13deg is a lot of operating angle to expect from a uni.

[Mr DJ]

Ok, hear what your saying tho why are vibes only present when coasting ?
On rig, flange to flange is 1120mm with 300mm height seperation between flanges.
4" lift & have raised transfer output a little during 5.0 conversion but not a huge amount as there is no BL.

[AussieCJ7]

you dont say what this is in but assuming its a factory D300 then your talking CJ7 with a 4" lift let alone lifting the output through drive line mods you will almost certainly need a double cardin drive shaft The rear shaft in a CJ7 was short from the factory add any angle and it need help

[Mr DJ]

it's a kind of a bitsa .....
91 Surf, coil SAS from a Bundera, Ford 5.0 & AOD trans with D300 transfer.
Not a factory D300 either, upgraded input, F&R output, clocking ring & 4:1 reduction.
The existing shaft had to be extended to mate to the new drive line.

Have to pull the transfer and go back through it I think

[Mr DJ]

Have finally found time to pull out gearbox & transfer.
Transfer seems great, only movement is tiny bit between gears (bout 1/8 at outside edge of drive flange) and some in the sliding gears.
Thinking the sliding gear where the guides sit may have worn too much allowing extra movement. These are one of the fer things not replaced during the upgrades.
Have put up a vid of the movement, tell me what you think.
http://s78.photobucket.com/albums/j101/ ... CF5531.mp4" onclick="window.open(this.href);return false;

Normal or not ???

[Mr DJ]

It seems that movement is normal ...... gearbox is next

Thanks for the help guys.