Thread: diff upgrade options

socket or spanner haha. I cant see how you would get a socket with any driving device attached. I have some nice Snap-on Hi performance 12 point ring spanners. The 14-17mm version is their longest in 14mm so you can get some good torque on those double hex bolts.

but yes tool clearance was my reasoning for maybe a smaller dia bolt between the others? this may be of some help to the 7 bolt swivels. Or a person could cut off the axle flange machine a new one and weld up the holes in the swivels flange and add as many bolts as posible all the way around, allowing of coarse for tool size to tighten the bolts. I have seen high pressure flanges on pipe work that has bolts almost touching all the way around. I figure there must be some small similarity in these???

Originally Posted by Bush65

how much you slot the holes depends on how much castor correction is needed.

Thick washers will help with the fatigue strength og the bolts, also not having the slot extend past the shank of the bolts, i.e. don't make the slots any longer than necessary. For fatigue strength it is necessary to maximise the area of flange that is under compression when the bolt is tightened - this area is a sort of cone shape region, through the flange from the underside of the bolt head, i.e. it enlarges as the compression extends through the thickness of the flange. Slotting reduces the area, and the thick washer helps to restore some (but not all) of the lost area.

Edit: these bolts loosen or break because because the fatigue strength is reduced by insufficient pre-tension or because stiffness of the flange in the area under the bolt head is reduced (gasket instead of metal to metal joint, thick sealant or dirt in the joint, or mating surfaces not flat (burred).

Not sure which diff housing chief is using.

I slotted the 74 RR balls from my POS and welded up the slots so that effectively the holes just got moved. Was really easy to do in sequence after slotting on the end of a spare housing using an old oily bolt that the weld wouldn't stick to. I just ground the excess off the outside with an angle grinder.

Note: the flanges on the other balls I have (81 RR) are at least 20% thicker than the 74 ones for whatever reason. Internals are the same and internal spacing has been adjusted at the factory. I'd use those next time.

I used the widest thickest washers I could find under the bolt heads. No probs to date. (80 thou)

cheers, DL

i am using a 1986 110 diff housing and have 7 bolts...how did you slot your holes? and also with welding was it easy or was it a mission? as i was wondering if oil impregnation may have occured to the steel making welding difficult...
i am going to slot holes use thick washers as previously stated then for extra security i am considering drilling a 10mm hole through swivel ball flange and then assembling it all back together to new adjustment point then marking diff side flange then remove swivel ball again drill and tap diff side flange and then i will have a lock bolt so to speak...

Hi Chief,

Made a circular jig out of ply clamped to a drill press with a slotting bit. Bit tedious as the flanges are quite hard. You have to double check you're clocking the holes the right way!!

I am no gun welder. All traces of oil were removed from the flanges, balls were mounted on a spare housing using two opposite bolts in the new rotated position. Slots were filled with weld one by one using an old oily bolt in each as I went. Surprisingly easy. Cleaned up the outer surface carefully with a 4" grinder.

cheers, DL

mmmm interesting...any pics of the process?
one advantage of how you do it was that the holes were already slotted then you welded but the problem i can see with welding holes prior then drilling new holes is that no matter how good your marking out is it will never be spot on compared to the other side...
i have already marked the direction of where the slots will need to go (hopefully my mind didnt slip up that day ) then use a dividing head on the mill and see how well it turns out i shal post pics up when im doing it if i can figure out how

Hi again,

Slot first, rotate, then fill the slots to create holes only. Was a long while ago and I think I was going for 7 degrees.

To get them the same you just pick a slot on each that is closest to the end rotation you were after and use that as your reference (leave a bolt in that slot end) when welding up the rest.

Don't have pics and a milling machine would be a gazillion times better than doing it the way I did.

cheers, DL

If you slot them in a mill over 5 degree's, they aill leave an edge that is good enough to stop any rotation, I ran these for years

If you wanna build diffs, get a front sals, convert rear to 35 spline front to 30, if you wanna do diffs on a budget, use GU 3.5 ratio diff's

I have a question, all this theory and all these posts, do you have the time and dollars to achieve what your after? none of this stuff is new, no leadin edge technology, its all been doneded beforeded

You need to answer 3 things

1. your budget
2. The desired result
3. what your capability (hands on to build stuff) is

Simply mathematics will tell you if its viable

Originally Posted by rovercare

If you slot them in a mill over 5 degree's, they aill leave an edge that is good enough to stop any rotation, I ran these for years

If you wanna build diffs, get a front sals, convert rear to 35 spline front to 30, if you wanna do diffs on a budget, use GU 3.5 ratio diff's

I have a question, all this theory and all these posts, do you have the time and dollars to achieve what your after? none of this stuff is new, no leadin edge technology, its all been doneded beforeded

You need to answer 3 things

1. your budget
2. The desired result
3. what your capability (hands on to build stuff) is

Simply mathematics will tell you if its viable

That's about the guts of it.

Time - wise I had the slotting bit already: then balls off, made the jig, slotted the holes, welded up the slots, re-assembled all in a day. Welding part was quick, slotting was slowest but a mill would be much quicker.

Then took the POS for a drive.....................no more shopping trolley.

DL