strengthening diffs for jumps

[Wambat]

hey guy take a look at this page.

http://www.outerlimits4x4.com/viewtopic ... 4&t=217226" onclick="window.open(this.href);return false;

i attended this event, and it was an awesome week end. but now i want to go back and compete.

some of the cars that done well on the day were standard. with how the track is designed your under diff clearance wouldnt be an issue, so if you were to strengthen your diffs buy putting more meat on them(laminating??) top and bottom, how would you go about it?? where do you weld stuff up to on the ball of the swivel hub?? how do you weld the axle tubes, i would assume stiches of 100mm or so so as to not get too much heat into it??

[rockcrawler31]

hey guy take a look at this page.

http://www.outerlimits4x4.com/viewtopic ... 4&t=217226" onclick="window.open(this.href);return false;

i attended this event, and it was an awesome week end. but now i want to go back and compete.

some of the cars that done well on the day were standard. with how the track is designed your under diff clearance wouldnt be an issue, so if you were to strengthen your diffs buy putting more meat on them(laminating??) top and bottom, how would you go about it?? where do you weld stuff up to on the ball of the swivel hub?? how do you weld the axle tubes, i would assume stiches of 100mm or so so as to not get too much heat into it??

Seriously, google is your friend. I don't normally say this but search noob. There have been that many threads about laminating diffs it's not funny, you can see the basics there, and when you have a more in-depth question about a particular part of the process then come back and post that.

[toughnut]

Milo is talking from experience. How much pressure did it take to straighten your diff housing milo???

[rockcrawler31]

Milo is talking from experience. How much pressure did it take to straighten your diff housing milo???

If i recall correctly it was 8000lb for the front and about 19000lb for the rear

Jacmac had his press maxxed out

[1MadEngineer]

If i recall correctly it was 8000lb for the front and about 19000lb for the rear

Jacmac had his press maxxed out

must be a toy press, 19000lb (8.6t).

[rockcrawler31]

If i recall correctly it was 8000lb for the front and about 19000lb for the rear

Jacmac had his press maxxed out

must be a toy press, 19000lb (8.6t).

maybe i have the units wrong, it WAS 12 months ago and i can't usually remember what i had for breakfast. Either way way there was/is a nice divot in the middle of the housing where the ram block deformed it. I'm sure the big arse bridge across the top of the housing for the triangulated top links didn't help.

ON a more related note to the OP though, has anybody found if the chroming/polishing on the swivels has been an issue for welding the knuckle strengthening tags? Does the chroming need to be ground back or is it normally just a polished mild steel surface?

[toughnut]

I had no worries welding mine. When you do just put a small tac on first then move your wheels from lock to lock to make sure they clear the botls at the back of your swivel hub. Didn't do that the first time on my patrol and they acted like steering stops and made my turning circle larger. Made it an issue on tight tracks.

[Wambat]

thanks guys,

im not a newbie to this site, i didnt search cause i already understand the basics, and cause i now highly dislike the search function, every time i have used it it has been hard to get the answers im searching for.

my main question would more relate to the ends of the laminating, like where the ubolt plates are and the u bolts. cause i cant see a way to keep one length of steel going through there. maybe with the ubolts (have holes in the steel to allow the ubolts to turn so you can take them out if needed) but the bottom where the ubolt plate is is where i dont know how to get the strength. and then like i said the welding to stop it from warping, ill do a search but if i dont find the answers i want or more so need, ill be posting back here.

[Wambat]

ok so i did a search, and checked websites like cheezy and that(as thats where google took me) and looked through here, and a few other forums. one of which mentioned that the house can warp, which i knew. and the method for stoping that is to do it on a jig, or straighten it after the fact.

so my question is, when doing the main supports. the welding runs are long, so if you cant get it on a jig and dont want to bend it, if you had everything tacked in place, and did a couple 1 inch runs at selected points, (first on near pumkin, next one at the oposite side near spring hanger, then nexe one in the middle on the oposite side, then next one at pumkin again, and next one in the middle again on other side, and then again back at the spring hanger) so that was confusing, i basicaly mean, zig zaging untill you have done enough welds to counter act the heat being put in buy the next one to stop it beinding?? i understand what i mean, it was something i was taught buy the boiler maker i did my apprentice ship with. but as you then have basicaly 4 sections to do, if you did one top first that would still have a chance of bending, so i would assume, you would have to zig zag through the top and bottom of each side first then continue zig zaging to fill the spaces.

ive done that on straight flat steel that we needed straight and it worked without pulling. but it was one flat piece on another, not two round tubes welding on 4 supports on top and bottom.


i think im more confused now that when this all begun. but i stil have a good idea on what i would be doing,

[toughnut]

I haven't been in the comp scene for a little while but with mine I only braced the top of the diff housing and double skinned the bottom half along with bracing plates in the knuckles top and bottom. I left my diff assembled and had as much oil as I could fit in there to keep things cooler while welding then changed the oil afterward. It didn't burn any seals and I didn't need to rebuild the diff for another 12 months of driving and competing. I and most others only brace out to the spring mounts be they either coil or leaf.

[Wambat]

the bracing will be happening on a leaf 60 series me thinks. as i am only thinking about entering the event that i posted up the top, and having under the diff braced wont effect the clearance for the event i think ill do both.

but we will see, this will be the first time i do it and it wont be on my daily driver so i wont be to fused if i mess up, i need to learn new things haha.

[toughnut]

For the lower section you could maybe put a peaked section in instead of square box. Think of the box bracing turned on an angle so it will slide over obstacles instead of hitting with a flat face if you do decide to do other stuff with it. Just a thought.

[Wambat]

you mean use angline??? right angle section.

yeah i could, i have thought of that, but its the shaping it to taper out towards the hubs that would be the harder part with angline.

also where do people brace to on the rear of the car?? right up to the brake guard?? ive not seen rear diff bracing.

[toughnut]

Brace the rear the same as the front. A lot of people also brace across the back of the pumpkin basicall from one shock mount to the other.

[Wambat]

where do you end the bracing on the back so that you can still get bits off your car if needed??? on the front ya can go up to the ball for the swivels ive seen pictures of that, and like the advice some one gave earlier about checking with a tac and then turning the steering was good advise

[Z()LTAN]

This is what we did on a mates 60 rear housing.

75x75x8mm box, if clearance isnt an issue you could do the same to the bottom.

[Wambat]

hey zoltan, that is pretty much what i have in mind, how did you make sure you didnt warp the housing??? thats the bit i am most interested in at the moment. clearance wont be that much of an issue, so what you have shown is pretty much what i would be doing top and bottom, but i will probably cut an angle into the bottom so that it tapers away from the pumpkin to the ends,

[Z()LTAN]

weld slow and take your time. weld no more than 50mm at a time and back step/checker the welds

if your bracing top and bottom it will be much easier not to warp the housing. Tac all the pieces on then stitch it all together top and bottom at the same time.

[hulsty]

the bracing will be happening on a leaf 60 series me thinks.

Use late model 60 series diffs and they are already braced on the underside from the factory. About 1988 onwards I think it was.

[Wambat]

really, i thought that was just the housing its self to get more oil in the front diff cause of the shorter length between axle seals than the back . ah well bonus

[ISUZUROVER]

Here is my (Landrover) front.



4 mm RHS cut down for the main brace.
Diff pan replaced by 8 mm Butt Weld Pipe Cap
4 mm flat bar over the top of the centre up to the bump stop pad.

NB - the vehicle is mainly a tourer. I would have braced it more extensively for "jumps"
- I also "pre-stressed" the housing to counteract any distortion from welding.

[Wambat]

cheers for the pic, thats the main way i have been thinking of doing it, just on both top and bottom

[v840]

What's the difference between bracing the diff "on top" and running the bracing "behind" the diff?

I'm just curious because often the "on top" bracing has to run around shock mounts, spring perches and link mounts which is a bit of a PITA.

[Wambat]

from what i understand the behind the diff bracing is to stop you smashing in the diff pumpkin and having it wear against the teeth of the diff gears?? thats my understanding it.

on top of the diff will stop the upward flex that can happen as a result of the the sudden stop of the wheels hitting the ground with force. same with underneath,

if you were to put the bracing on the back of the diff rather than on top, it would still help but to a lesser degree.

well thats my understanding any way, you always brace the side that will flex on something that's going to or possibly could.