DIFF HELP PLEASE ????????

[Blown_FC]

 I recently sent my HR diff ( from my FC ), to be reset with new fine spline axles, spider gears, bearings ect ect, and have just been informed that my HR diff is in fact a HK diff

This has posed problems, as we can not find  a fine spline spider gear set any where in the country.

I originally wanted an LSD aswell, but can't find one of those either.

My question is........IS A HK DIFF ANY STRONGER OR BIGGER THAN THE HR UNIT

I am looking down the barrell of running the original COARSE spline axles, with a new 2nd hand set of SPider Gears, and the original 3:08 centre....so I'm hoping that it will be strong enough to run my XU1 202 motor with a Street Launcher Converter ( 2100 stall ), and re-worked and shift kitted Trimatic.

Any comments or ideas

[Jockster]

Try to get hold of an LX SLR 5000 LSD centre, they are fine splined and the right ratio and will bolt into your housing
Cheers
Jock

[Blown_FC]

Thanks for that Jock...may have to revisit my budget plans....as the guy who has the diff also agreed with you, but then the axles won't fit, so it's a case of cutting and rewelding / re-splining a new set of axles to fit, which then ( if you can even find a SLR 5000 diff ), racks up the dollars mighty quick......the basic diff work I'm getting done is already over $1000......for $1500 I can get a full conversion from a Borg Warner Diff with Disc Braked ends, fully welded and set up for putting into an FC....so I didn;t want to go too crazy on dollars refitting the old banjo, when a full conversion is $500 more than where I'm at , at present !

I guess, that's why I'm hoping the HK banjo is stornger than a FC or HR Banjo anyway...taht' will put my mind at rest.

Cheers
Mark

[oldgmh]

Hey Blownup FC,

If you are just after fine spline diff parts then look for a HZ diff as I am quite sure they were all fine spline.  They are interchangeable with all early diffs in the housing department, as long as you have fine spline axles to match.

Regards,
Earlee

[FCwagon]

Hi Mark,
The HK diff in theory should be as strong or stronger than a HR unit. They did after all have a V8 driving some of them with only a bigger yoke.
You could also look at any late Torana diff. I used a 3.08 diff from a UC Sunbird in my wagon but went the other way and changed the fine spline spider gears in the Torana diff for the ones out of the HR diff.
It's not a hard job rebuilding diffs and the bearings are just ordinary so I don't know why the high prices.
Hope this helps
Leigh

[Blown_FC]

Thanks Leigh and Earlee for your thoughts....the hard bit is not doing the work, I think it's more a case of trying to find the parts.

To find FINE SPLINE axles that fit without cutting and rewelding, and fine spline spider gears ect ect, is proving to be the hard part.

I was just more surpised about it being a HK diff, as I didn't think they fitted into FC's.....if it was a hR diff as originally thought, I would have found the parts by now, but apparantly HK is a different story.

Thanks again for your feedback

Cheers
Mark

[Effie C]

Mark, It would be a HR diff housing with a HK centre. I have a HQ diff centre fitted to my HR housing. HQ also had LSD with fine spline once again length of axles will be a pain.
John M

[Blown_FC]

Now that makes more sense.....I must sound so green at times....

SO I obviously need to source a set of HR Fine Spline Axles and diff centre

Thanks John

Mark

[Blown_FC]

Thanks to all those who helped with my enquiry.

Good news....I have found a HR LSD centre (3.36) that will fit straight into my HR Housing, and using my existing Axles......$550....plus $300 for new seals. bearings, and labour, gives me a pretty good diff for my project at only $850 !

The guy selling the LSD assures me of it's quality, and that it is one of the better ones hes seen in the last 15 years....and has agreed that I let a Auto mob pull it apart and inspect it, and if it's found to be stuffed, he will take it back and refund my money.......this is how confident he is about how good the diff actually is.

This gives me confidence and peace of mind.

It pays to ask heaps of people and makes lots of calls.

Cheers

So for those interested in what my set up will finally be....

- XU1 Red Motor 202 with Triple CD 150 Strombergs
- XU1 Cam
- Stage 3 Head with YT roller rockers
- Street Launcher 2100 stall converter
- Shift Kitted and re-worked ( to V8 specs ) Trimatic complete with Corvette pistons, chevlar belts ect.
- HR LSD 3.36 Diff

Hmmmm....starting to sound just about right !

Let's just hope it all works as good in real life, as it does on paper !

Cheers

Mark

[ChrisB]

Mark,
Good to see you have a cheaper alternative, I am using a HQ 3.55 diff centre in my FC housing with the original axles


ChrisB  

[Blown_FC]

CHris.......what motor / gbox are you running, and how do you find the 3.55 ratio?

Mark

[Jockster]

G'day again Mark,
If its any help I am running a HR rear end in my FC with a 3.08:1 HT V8 Diff and coarse splined axles. It has on the odd occasion been known to spin its wheels on bitumen (accidentaly of course) and so far over 7 years has not had any problems with the axles. The ratio is a little high for the 14 inch wheels, no problems down low it still accelerates quite rapidly, but I can only use 3rd gear around town, 4th is a tiny bit too high, conversly it is a very economic open road car.
Cheers
Jock

[ChrisB]

Mark, I have a grey with a little cam and standard gearbox. It does not get off the line as quick as the 3.89 but its not that far behind, but at higher speeds the motor is not as stressed. I use to hate running over 60 mph because the poor thing use to sound like it was reving its guts out. I tried the 3.36 but did not like the extra effort to get it away. The 3.55 has been the best for my old girl

ChrisB  

[nicko]

Hi, check out link i have just posted in auction and trade section ,good LSD banjo centre.
reguards Nick

[blown red]

 Hey there Mark.

   Not sure if you have read my part on freezing engine parts, but there is a mob in Sydney who can frezze just about anything(includung diff centers) that will double its strength.

    I will be doing this when i get to that stage of my project (HR with blown 6), just to see how good this stuff really is.

    I know you are all thinking that it is too good to be true, and that i have my hand on it...

    But what if they were onto something.

    Its as cheap as chips so i cant see the halm in trying it.

    NASA, apparently discovered it when the space shutles were coming back twice as hard as when they sent them up there.

    They found that on re-entry they froze to a certain temperature increasing their strength.

     I can put you onto the mob if like.Let me know.

    Cheers
   
     Ben  

[Blown_FC]

sounds good, i'm into things that are different...but about a week too late...the diff is already being worked on, and about to be shipped back to me...but would be keen to know more about this freezing thing....maybe it's a bit live the reverse of heating something....when you heat something up, and cool it quickly and allow it to cool again, it comes back softer and more malleable....?

Cheers

mark

[blown red]

  Hey there blown_fc. The place is in Sydney, and they are called Cryotuff.
 
  For $5 a kilo you cant realy go wrong.They must be able to do any size.
 
  Im thinking of even going with my engine block, so that i can have my crank gernals (not sure on spelling) done.
 
  They do blocks but he said around $500 for something that heavy.

  Hope that helps you!
  blown red.

[Blown_FC]

Thanks for that....but at $500 a block plus that again for freight...I could buy 9 or 10 red motor blocks.

However, I could see the benefit in smaller items.

Would be good if Street Machine or someone did a test and article on it, as if it does what they say it does, they could make a lot of money from a good rap....but if it's hocus pocus, then we'll save our money !

May be worth getting a small TEST piece done, and have it's strength tested by a machine shop before and after to test teh strength and integrity of the metal....if it comes back stronger tahn I say go for it !

Cheers

Then again...my red motor has lasted 30 odd years already......if I get than much again, I'd be happy



Mark

[blown red]

  Thats right. If its lasted this long now, why change it.

  The only reason that im getting it done is that i have spoken to various engine builders and they say that the only way to get serious mumbo from a holden 6 is to make it rev.

   I am looking at around 300-400 HP(blown), and ive been told that my engine will need to rev from 7500-8000 rpm to make that sort of hp.I dont want anything to go bang at those rpms.

   It will still be another 3 - 6 months untill its all back together, and back in the car(HR), but i will be letting you guys know how i go as soon as its running.

   cheers

  blown red