Pinion Angle

[splitty]

Hi Guys

I need some info on setting pinion angle on my diff. Have got 6 Degrees on rear of  turbo 350 transmission , do I set the diff pinion at 6 degrees opposite.

Gaz

[FCRB26]

I always run 3 degrees down when doing diffs.

Thats my preference tho dunno what others thoughts are


Pete

[slack one]

hi all i have ran at 4 degrees to the up.cheers gazza.

[john253a]

the angle mean little without references

there is also a program you can get to calculate it if you want,

normally 1deg down on box between 3-4up on diff with 0 on car, tali shaft should be a 0 deg phase

[splitty]

HI John,

References are the rear seal housing on the transmission is 6* down angle as governed by the Hadfield set up. Do I set the diff pinion flange to show what angle . Down or up ?

Thanks

Gaz

[FC427]

HI John,

References are the rear seal housing on the transmission is 6* down angle as governed by the Hadfield set up. Do I set the diff pinion flange to show what angle . Down or up ?

Thanks

Gaz

I always set the diff angle at 2deg down from the gearbox angle as the diff usually winds up around this much when power is transmitted ........FC427.......

[splitty]

FC 427,

Hi thanks for your help , my engine / tranny set up is facing 6 *down , do yu mean i set the diff at 4 * down as well. I think Im gonna have too google some more info   lol

[FC427]

FC 427,

Hi thanks for your help , my engine / tranny set up is facing 6 *down , do yu mean i set the diff at 4 * down as well. I think Im gonna have too google some more info   lol

If  your g/box angle is 6* facing down with the car on on level ground you would need the  the pinion to be 6* + 2* = 8*  down

[Ed]

the diff should be between 4° to 6° UP. when gearbox is 6° DOWN.

if gearbox is down, diff pinion should be up the same amount, with a a tolerance of 2° as mentioned.

I would try get back to about 3 degrees by shimming your gearbox mount to move it up.

Cheers

Ed

[splitty]

Thanks everybody for your  info  ;)
Ed
FC 427
Slack
Pete


Cheers

Gaz

[waynos]

ed,
shouldnt carby be level at ride height and that will determine your gearbox shimming?
and adjust your diff as mentioned?

[waynos]

still wondering????????
what is fc or hr pinion angle standard?
i have a vibration  at 120 which i think is pinion angle.
is there a desired angle?
i thought as long as they were the same it was ok?
sorry to jack the thread.................

[FCRB26]

Im assuming its modified doing 120 so what tailshaft are you running ? i would check that and your unis before anything some tailshaft have carboard liner in them and they can come loose or let go for whatever reason.

But could be anything wheels drums axles output shaft ect ect.

Pete

[waynos]

hoon,
checked all of the above except new tailshaft
runnin hr i think ,unis etc are fine ,never thought of rear drums bein outta balance
yes is very modded.........
thinkin its the lowering blocks/pinion angle
all wheels are balanced cause i thought it was that
thanks mate

[Ed]

If you're getting vibration, check that your gearbox and pinion angles are within 2 degrees.

Ideally your carb should be level, yes but I don't think a couple of degrees at the gearbox will affect the float performance greatly.

Measure your angles of gearbox and diff and adjust accordingly.
If you are using lowering blocks perhaps it may be as easy as getting an engineering shop to just shave them down a touch for angle compensation.

I ironed out a similar vibration issue before and it was the angles of the uni joints, as described.  Rather than try change the angle of the diff using wedges, it was far easier to get an alloy block or similar and shim the trans mount up.

but your method of attack depends on which angle you are choosing to move.. diff or gearbox, up or down.

I checked the angle using a magnetic angle gauge, and all was fine.

Cheers

Ed

[Ed]

check your easy things first too..

Are your diff saddle rubbers in good nick?  old ones could be squashed and deformed giving you an incorrect pinion angle.

[FC427]

If you find that your pinion angle is incorrect rather than chopping the saddles of and rotating the diff housing you can buy wedges in different sizes 2* to 8*  that go under the saddle and the spring center bolt also goes through to correct the pinion angle with out any cutting or welding .....FC427.....

[FCV08]

Ed

I support your comment as I have set up the engine/gearbos in the same plane as the pinion using the magnetic angle guage.

Gaz

Has the tailshaft been balanced?

Cheers
Craig D

[waynos]

i havent got round to checkin angles,just figured the lowering blocks were changing the angle
and more than likely causin the vibration.
am gonna reverse the eyes and reset leaves myself in the press at work
so havent worried too much
but will definately check angles before i pull everything apart
am sure the pinion angles the prob
but it wont hurt to get the tailshaft balanced i spose
bought an unfinished project as some know
and i dont know what i got
it was a bunch a weird this and that
so who knows what tailshaft it is
its got balance weights and unis looked and felt fine
its gotta be pinion angle

[waynos]

oh yeah.
everything is replaced with nolathane bushes and saddle rubbers........
maybe no give??????????