GST Diffs for Site Jester

[Jt]

Ok guys yet another odd mod for Jt

We are going to tackle CEN GST diffs, and modding them to be run in a savage truck. I have done one set for myself but I will be showing what I have done for Site Jester, the local "Diff Stripper"

First lets see the CEN diff

Lets see 2 diffs totally tore down.

Some comparisons next to the Savage diff parts
out drives and pins, the Savage out drive cups need to be drilled out for the bigger CEN pin, because the CEN out drive is to short the dog bone could fall out if you used the CEN out drive cups

pinions

Ring and bevel gear

Spider bevel gears

The CEN bearing are metal shielded, we will use some rubber sealed bearing when we assemble the diff, here is also a center portion compared to a nova cup.

The spider bevel gears lightly greased on the back side to hold them to the block for assembly into the cup.

center sections 1 ring ring gear installed and the other with end cap installed

blocks and spider bevel gears installed into center sections

filled with oil

2 complete diff assemblies

the amount of shimming I used to fit the pinion for proper mesh to the ring gear in the "X" style diff housing

I couldn't get a real good pic but here is the diff in the housing meshed with the pinion

the savage pinion cup fits just fine on the CEN pinion you will need to grind off the pin portion of the screw off or if you have a plain grub screw that works just as well

here is the pinion cup attached to the pinion and the diff is ready for use as soon as the ring and pinion are greased

Enjoy Site Jester, lets see if you can make these last longer than a day. :stickspank:

 

[Jeremy]

oooooh man thats $%%$#^ sweet man hats off to you and the awesome work u put out there for us.... THANKS ALLOT !!!!!!!!!!!!!!!


Very good and detailed right up on the diffs man

 

[]-[0pa]0ng]

Really Nice write up Jt. Pics in all the right places worded correctly oh let's not forget SJ will be stoked. Those gears are impressive.

Thx for taking the time to do all this


Hop

 

[samisavage]

Wow those are alot beefier than the savage parts hopefully this will keep SJ bashing. thanks for the detailed description on the buildup. If these will hold up to The Master Diff Bashers abuse Some of us other less fortunate may be interested in the mod. Once again JT "YOU THE MAN" IMHO. Once again Nice work.

 

[Jeremy]

I need to say also, Jt recived the parts today and just informed that he will be sending them out tomorrow.. I love the service that he brings to hpisf!!! and we all can benefit from his awesome work...

 

[X25]

Great job JT. SJ try not to tear these up. Let us know how they do for you and all of that good stuff

 

[windjammr]

man you do some nice creative work,my truck is lot better off because i saw your mods here.Thanks i really appreciate all your hard work.

 

[Jt]

Thank you for the complement.

 

[JohnH]

once again nice
:FarleyParty:

 

[[hs] darkshine]

looks like they sould last more than 5 mins, even in sj's hands!! :Xfingers:

 

[Jeremy]

I plan on in the future to get some alloy bulkheads and cases, just to be on the safe side..... but if I strip these I have SERIOUS problems people(please don't comment on that) lol......

 

[Memnoch]

My only question is about gearing. Does this affect the overall gearing on the truck?

 

[Jt]

You will need to change the spur/CB to get the same ratio as if you were using stock diffs.
For comparsion in 3rd gear
stock is 14.61:1 when using 17/49 gearing
CEN is 14.45:1 when using 15/49 gearing
(Thanks to lizard for doing the math)

 

[DOOBEEWHA]

Great submission, JT. I guess that sts tourqe was the inspiration for this mod.

 

[Jeremy]

Most people don't have the kind of problems I had. I was at the end of my rope and desperate times call for desperate measure's. Allot of my problems come from the way I bash but I still think the savage need better quality diffs, They have been the same since day 1 and engines aren't getting smaller, more power means more problems and hpi needs to realize this WHO'S W/ ME ON THIS !!!!

 

[DOOBEEWHA]

I second the motion!

 

[samisavage]

I agree I'm now rebuilding another diff I blew after shimming perfectly gonna try the hardened diff sets I got if that don't work I will have to go to what U did. How they holding up and working for you SJ?

 

[Jeremy]

holding up good

 

[k0m0d067]

:FarleyParty: I'm jumping on the bandwagon finally...JT's agreed to do this mod for me as well...my first "JT's Mod"!! I'm stoked!!!:FarleyParty:

 

[Jeremy]

well so far there is still only 3 people on this fourm that have the cen diffs.. YOU WILL BE THE 4th congrats

 

[polystyrene]

nice thread, this mod of the cen diffs is easier to follow than the one from 'another savage forum'.

good to see more people catching onto this mod. been around for a while but nobody talks about it much

would be interesting to see how much those cen diffs can actually stand up to.

 

[Jeremy]

belive me they hold up

been threw a sts .30 and surefire allready

 

[k0m0d067]

if they can hold up to the local "diff stripper", they'll be good enough for me...LOL

 

[k0m0d067]

Just got mine back today!!! exactly 1 week from the day I sent my stuff to JT!!!

I have 2 words....


MMMMMMMMMMMMMMMMMMMMM!!!!! BEEFY!!!!!


these look awesome bud!!! can't wait to slap them in, and finish the rest of the racer up now!!!! :10: :10: :10: :10: :10:

 

[Jeremy]

Another happy customer !!!!! yeppers

 

[t0ttzg0tskillz]

crazy work man! you amaze me dude!

 

[xtremsavage]

Yeah, nice work Jt. Couple questions for you. What did you use for the shimming? What size drill bit did you use to drill out the drive cups? What weight oil did you use in the diffs for SJ?

 

[Jt]

Yeah, nice work Jt. Couple questions for you. What did you use for the shimming? What size drill bit did you use to drill out the drive cups? What weight oil did you use in the diffs for SJ?

Sorry for the delay in response (had some issues to resolve) anyway to answer your questions.

I use a custom shim (1 piece instead of a bunch off little ones) to get the mesh correct, I think I used a 3mm drill dit for the drive cups, and for the oil that comes down to driver preference...I have tried 50,000wt and I didnt like it personally so now I am using a blend of a 7,000wt and grease, still running that; not enough run time to determine what I like better.

 

[Jeremy]

I ran 10,000 it was ok ... but still a little more tweaking was needed

 

[CowBoyKillers]

ok i have a question how much does the gear reductions change the final drive ratio? Cause ive been wanting to change the drive ratio in my X but i don't want to do it threw CB's and Spurs. Its either the gears in the tranny or the diff's that gear the savage to low IMO. So if you could explain how much of a difference it made for example it would be like putting a 18 tooth CB in vs. the stock 15 tooth or swap the spur gear for CB just need an idea of how much it changed the drive ratio. Btw Great work JT.