D4 Tips
 

Hey all

a couple of building tips for you and things to watch.

dremel flat spots in the cvd's so the pins dont work themselves loose and also watch the diff bolts. they seem to be very fragile and we have broken two whilst adjusting the diffs and also had two failures mid race on the weekend.

problem has been solved by replacing them with a B4 diff bolt and nut.

apart from that the car is awesome. I had a BJ and if its possible the D4 steers even better...

Hi, any initial tips for this car? Mine should be here on thursday. I know that the diff screws are suspect and the drive pins need slotting but how is kit setup on grass/ astro etc?

Also, do the associated springs fit on to this car?

thanks

Hi
the diff screws are a problem but if you are careful when you tighten them they are fine do not do this quickly take your time.
Do not over tighten them. tighten the screw right up then back the screw off about a 1/4 of a turn to 3/8.
The slipper is very important you need to get the slipper to give before the diff this helps the diff screw.
I had Tonys set on the astro when dry at Kiddy at 3/8 to 1/2 a turn this should be ok make sure you locktite the screw as it will come undone.
There are some set up sheets on the HB web site will be putting more up as we go along. Sorry but this is work in progress as we test/race race at each venue.

Other than that the car is good sorry the results are not showing how good the car is at present.

Phill T

no associated springs do not fit. losi does though.

Another build
 

Hi

My car is built up to the point of the shocks. No paint on the body yet.

Diff Bolts:
I suggest to clean the bolt thread then screw into the nut and out before assembling in the diff.
Also squeese the spring in pliers before assembly.
Do not overtighten the diff bolt before backing off 1/4 turn. As long as the diff spur does not rotate as decribed in the check procedure.
It will need checking after running anyway.

Good build so far.

Any tips or points to watch out for with the shocks and setup?
I will be running on loose dusty tracks.

Jeff

Jeff

I would start with 35wt in the front, 30wt in the rear. blacks all round. #2 in front #3 in rear.

ride height as per manual. no sway bay. hole shots all round or bigshots in red on the rear.

this works good here in aus on loose surfaces.

ben

hi i not familiar with the B4, could you be kind enough to give me the part number i need? thank you

Ben

Did you pickup your D4 locally?

Looking for one and considering where to purchase, here or OS.

Are parts available here in Australia yet?

Thanks

Wayne

Hey wayne

got mine here from frontline hobbies in newcastle. 0249291140 speak to craig and he will sort you out. they are around $539 from memory. they have all the parts in stock and the prices are really good.

cheers
Ben

seem to have fixed the diff bolt issue. have gone to the HB Ti diff bolt and also been playing with the adjustment on the diffs, they seem very critical in their adjustment. other cars I have used tend to run the diffs close to locked up.

the D4 diffs run a lot looser than that. if you set them like the instructions show you they will be fine. I did this but then used my own in car test and determined they were too loose. turns out they were fine, not sure why but they do not slip at the same point other diffs will.

diff bolts have been fine for the last three meetings.

ben

Diff and Slipper setting
 

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

Does anyone know if losi shocks will go on the D4?
thanks

Hi Ben,

Thanks for the advice, talked to Craig. Great to talk to someone who knows his stuff.

Just waiting on stock.

Thanks

Wayne

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.?

We used PVA which is a sort of copydex glue that holds the rubber bits in place but you can still get them out if you need to.

Cam

:) 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?

joffacn, put a little bearing oil on your slipper bolt and run it through the nut before you assamble the slipper as I found that when I thought the slipper was tight it wasn't. The bolt hit a bit of swarf in the thread of the nut, car crawled forward with the slipper spinning. Cleaned the nut through, re-tightened the bolt and presto...
:)

In place of the rubber cement, i used a product for motocross grips called
RENTHAL Grip Glue. Used it when i used to race, and it stays supple.

done mine without tel, they carnt get out by the way they fit, and they are a tight fit in the hole once the pin is in.

thank you mr christopher, I was thinking of doing them without, cos like you say, they're not going anywhere.

I was just looking through the instructions thats all, and wondering why it was needed.

does "rubber cement" mean glue for sticking rubber, ie tyre glue

or does it mean a type of liquid rubber formula?

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.

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

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.

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.

:( 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!:)

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.

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:confused:

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

Phill T

Hope this helps.

Shock limiting
 

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

$!!$ Diff Nut
 

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

Diffs and slipper adjustment
 

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.

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!!

:) 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?:)

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 :)

RE: Diff Bolts
 

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

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

:) 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.:)

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.

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

HB D4 Build Tips
 

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