D4 Tips

[jimmy]

Something which can be removed I guess, something 'tacky' rather than permenent? Since from the sound of it, the glue is just to keep those parts in place.

I've no glue other than very thin super glue (tyre glue) so I'm sure I'd do the same as Mark and omit glue.

[ben27111973]

Originally Posted by joffacn

HI

Diff: Just tight enough not to slip when holding the outdrives - as per the manual.
What adjustments to suit track conditions? What are the indicators and effects of too tight or too loose?

Slipper: Is the instruction to:
1. tighten all the way.
2. loosen 1 full turn plus 1/4 turn OR is it to loosen ONE only 1/4 turn?

The slipper should SLIP when the wheels are held and the spur turned with some reasonable force - correct?

How much slip is advisable?
Should the slipper "slip" for a metre or so when accelerating hard?
Should this amount of slip be adjusted for the amount of grip on each type of surface?
That is on a low grip surface I should loosen the slipper to get some slip on hard acceleration rather than get a lot of wheel spin?


Thanks Jeff

Jeff

Adjust diffs as per manual and you will have no issue.

Slipper is not there to control traction or to "slip" its to provide some protection for the drivetrain when jumping etc.

You should set it 1/2 turn out from locked and make sure you use a good quality loctite.

The car should launch hard and straight, if anything is slipping it will be the diffs as the slipper will not present any noticable slip when its a 1/2 turn out.

cheers
Ben

[ben27111973]

Originally Posted by telboy

Just looking throught the instructions.

It says to use some 'rubber cement' on the hinge pin blocks.
Any advice on what to use as I have never used the stuff before, or shall I just use something else.?

I have had no issue using nothing.

If you are after the rubber cement though I have found it at an arts and crafts shop here in aus. hardware stores and general shops had no idea.

[ben27111973]

Originally Posted by gramey

Little Mac, You told me to use Evostick! I hope I can get them out when I need to.............

ben27111973, I've only run mine for 1 meeting, next one coming up this Sunday, but on reading the bit about diff bolts before I got and assembled mine I used Tamiya 25mm diff bolts with no problems. Are the Ti ones listed as an option or do you have a part number?

61089 Titanium coat diff. screw M2x27mm

not sure how much stronger they are as they are only coated but I have had no issue with these at all.

[gramey]

That was tempting fate wasn't it, rear diff screw snapped in half yesterday, what a bu**er!, not to mention losing the cross pin on the rear centre drive shaft twice! 3 races with front wheel drive only after only a few laps truely sucked....
I'd applied thread lock on all the grub screws and put flats on the drive shaft cross pins but hadn't bothered putting a flat on the centre shaft cross pins. I shall now remedy that minor issue and I'm also going to file/dremel a small semi circle at 90 degrees to each cross pin hole. I don't seem to be able to get a hex drive squarely onto the grub screws so I'm thinking they may not be going as tight as they could. With a little easier access to them I should be able to get a good solid drive on them and tighten them down till they squeak!

[ben27111973]

I did another diff screw on the weekend. it was an associated one and it was set as per manual. so it looks like the issue still exists.

It would be nice to know what is causing this, the screw is shearing at exactly the same point each time it breaks - right up against the nut.

Anyone got any ideas on this? besides the diff spring on the opposite side its the same as all the other diffs out there....

Am going to try installing a different spring, there has been some success using the associated B4 diff spring here in AUS. With that spring installed the D4 driver has not broken a diff screw yet.

[PTRU]

Hi all

I am now lifing this part I change it when I re build the diff.

Tony did one National one test 8 packs of batteries. 2 club meets and a regional several meetings before I rebuilt the diff to give you an idea of the length of running.
This was all on high grip tracks in the UK.

I still use the same methord of building the diff as previous post I do not over tighten the screw before backing it off. Touch wood we have not snaped a screw for some time now. Hope that is not a Murry Walker

I found it was always the rear that went never the front.

Phill T

Hope this helps.

[joffacn]

Hi

Let me see if I have this correct.
Shock limiting has an effect on the downtravel of the wheel.
What does this effect on the handling?

How do you make this adjustment on the D4?

Jeff

[joffacn]

HELP!!!

My threadlocker was too much or too strong. When I tried to tighten the diff the metal insert in the diff nut just spun inside the plastic part of the nut.

The means I can remove the plastic part but the metal part of the nut is still deep inside the outdrive and threadlocked to the diff bolt. I cannot tighten or remove the diff bolt.

ANY IDEAS to remove?

What is a substitute replacement part with a full metal nut like on the slipper? These are M2 bolt and 2 mm special nut.
OR
Does the plastic part of the diff nut hold it in place without threadlock?

Thanks Jeff

[Somerwil]

Hi guys,

I gave my D4 some runs today and here's what I've found:

The bad:
The first race my rear standard diff bolt broke. I read about that here on the forum but my car was already put together and I decided to give it a try. The second race I ended up with a slipping front diff. I tried to adjust that but by doing that, the bolt broke as well. I replaced both the bolts by Associated diff bolts. The 3rd battery was quiet OK, but I thought it would be a good idea to loosen the slipper clutch after that run. This slipper clutch is pretty critical and cannot be tested or adjusted easily. At least not in a way that I know of. This is the way I do it now: I take the driveline apart (remove the alu part on top of the motor mount), take the slipper out, adjust the clutch, put the driveline together and give it a try...
It took 4 tries before I felt is was set right.

After loosening the slipper I gave the car a 4th pack resulting in another broken Associated diff screw.

Conclusion: 4 packs, 3 diff screws. Besides that, setting the slipper cannot be done easily.

Here comes the gooed news:
Apart from the problems, I found that the car was really good around the track. I think my Inside Jobs weren't all that great in forward traction on our local track, but I will have to wait for the 61499 Losi converters to run other tyres... The basic setup is pretty good actually. I would recommend 35-40WT up front and 30WT on the back end of the car. The manual tells you to run 30WT in all dampers.

Gr,
Michael

BTW: Our track is 50% clay (with a pretty loose surface) and 50% carpet which makes is difficult to find the best tyre. On a 2WD we normally use Big Shots or Medial Pro Crysp.

[mark christopher]

how i set slipper is both top decks off slipper top plate off and lift it out, takes couple of mins.

had 5 packs through mine on standard diff bolts niether are slipping!!

[gramey]

I'm wondering if it's the slipper being too tight that is causing the diff bolts to shear. Any recommendations on how tight or loose to run the slipper and would running it to tight be the cause of the problem?

[Ron Burgundy]

I dont think its the slipper...

Its a cyclone....(touring car) inherent problem too.

It has something to do with the design of the diffs/spring on the bolt side etc and the slight twisting of the diff under load.

so i have heard

[mharlow]

We have had trouble with the Diff Bolts as well. We have also had associated bolts snap on us. So it is not the bolt that is the weak point it is something else. The only difference in the diffs compared to the BJ4 is that the spring is under the thrust race on the D4 and it is on the nut side on the BJ4. I think this has something to do with it. I've also noticed that the thrust race washers on the D4 are thinner than the Associated ones and I have had two of these explode on me. I will be trying full associated hardware this weekend eg. Bolt, Thrust Washers and Spring and I will report back on how this goes.

I also read a comment on the USA thread that the US version is being released with upgraded diffs (hence the delay). I don't now how true this is as I have not been able to find any info on the Hot Bodies web site.

Regards

Michael

[GRIFF55]

Any joy on running full associated hardware(diffs)??

[gramey]

I'm currently building up my son's D4 for him and did what I said in my earlier post with regard to dremelling a small semi circle on each of the diff drive cups & axles. I'm not sure if it will make any difference to helping retain the cross pins, which I've filed flats onto, but it certainly makes access to the grub screws easier. I can now tighten them down without rounding out the screws.

[telboy]

had 5 packs through mine on standard diff bolts niether are slipping!!

run mine for two meetings now, with no problems with the diff screw.

the rear loosened off twice at the weekend but that was down to my P.P.P. and not threadlocking the screw when I re-built the diff in the week.

so far there's been no probs with mine. other than obvious poor prep issues.

....make sure you threadlock where it tells you to.

[mharlow]

Originally Posted by mharlow

We have had trouble with the Diff Bolts as well. We have also had associated bolts snap on us. So it is not the bolt that is the weak point it is something else. The only difference in the diffs compared to the BJ4 is that the spring is under the thrust race on the D4 and it is on the nut side on the BJ4. I think this has something to do with it. I've also noticed that the thrust race washers on the D4 are thinner than the Associated ones and I have had two of these explode on me. I will be trying full associated hardware this weekend eg. Bolt, Thrust Washers and Spring and I will report back on how this goes.

I also read a comment on the USA thread that the US version is being released with upgraded diffs (hence the delay). I don't now how true this is as I have not been able to find any info on the Hot Bodies web site.

Regards

Michael

I ran the full associated hardware on the weekend with no issues. Fingers crossed this will get me through until the upgraded bolts are in stock. I will let you know if I have any issues with the associated hardware. I like the look of the associated spring as the HPI one does not look as ground down. Also I found that the HPI seems to lose a lot of tension after you have run it.

Regards

Michael

[Jamesy]

Hotbodies have put up some build tips for the D4 on there website:-

http://www.hbeurope.com/news/en/2007070601.html

Also they have updated the kit page with loads more information on the car:-

http://www.hbeurope.com/kit.php?partNo=61410&lang=en