Broken Axle Studs and possible mod to 10mm Studs

[evil_hitman]

Hi All,
Well when changing wheel bearings on the rear of my troopy (HJ75), we managed to shear off one of the axle studs. The next day i proceded to break an easy out off inside. Anyway. Driving around some time in the last few days, 2 more axle studs have sheared off. Hubs are due for replacement anyway so i'm just going to change them.

My question is, Has anybody re-drilled and tapped the hubs and had the axles machined to use the 10mm Studs rather than the 8mm studs that are standard. Or are the 8mm ones good enough and mine just broke because of the 325,000km plus that this vehicle has done.

Thanks

Matt

[grub_80]

I have broken studs on front and have seen studs break on rear all whilst driving on tracks. I have an 80 series and mine have been drilled out to 3/8 and had new tapered collets machined I have 12 bolts holding rear and 8 on the front as I now no longer have the dowels.

[GRINCH]

from what ive heard thats a common problem for toyotas

[RV80]

Expect to pay a couple hundred bucks to convert it to 10mm.

Regular maintance would of prevented this. Just replace them
all with new 8mm ones. I paid $2.00ea for a new stud, cone and
washer kit .

[evil_hitman]

well another stud has gone leaving me 2. Looking at the remaining bits of the broken studs it appears as if they were already broken part way through.

Conversion to 10mm will cost me $50 an axle (for machining of the axle to suit the new cones) I intend on getting new studs, cones, hubs anyway so it's not much more. The main thing that worries me is if i go touring. Parts wont be available off the shelf / off the station owners junk cars.

I've only had this / a 4x4 for 5 months. what sort of maintenence do you do on a stud?

Matt

PS Switching to front wheel drive to save what remaining studs i have until next weekend.

[RV80]

what sort of maintenence do you do on a stud?

When they done as many kay's as yours has and when you don't
know the history of the vehicle, replace them all. A full stud kit
will cost under $50. Save the headaches later on.

[evil_hitman]

thats the sort of thing that i'm doing at the moment. unfortunately the studs broke before i got to that part. :(

thanks guys

[beanz2]

This is how my hub studs looked like only after 97000 kms:



The gasket space between the wheel hub and the axle seems to trap water and this causes the studs to rust. This is how the one of the studs looks like after cleaning the rust off:



I first saw the 10 mm stud conversion described in detail by dumbdunce (Brian) on this board, but the idea was met with lukewarm reception in the US. Some have expressed concerns about the thickness of the material left in the hub body if the holes are drilled to 10mm, some others have had difficulty finding the necessary tooling to re-taper the locking hub and axle to accept the 10 mm studs and cone washers.

This is the current "hot" set up in the US:



Four additional dowels are added to the hub to carry the load that was carried by the two original dowels. The studs are replaced by grade 8 studs.

Dave

[evil_hitman]

this looks to be the go.
do you have any more info on this mod?
by the looks of the pic thats for a front wheel. might do the fronts as well considering i'm about to up the tyre size and will soon put lockers front and back.

[beanz2]

Yes, these are mainly done to Hilux and Landcruiser front axles as our rear axles are mainly semi floaters.

The 6 dowel modification is done by Hendrix Motorsports. It is spendy, about US$120 per axle IIRC. I've thought of doing it myself but they use a CNC mill and a custom jig to redrill the hubs to ensure that the holes are placed such that the holes on the locking hub, and the spares match perfectly.

The grade 8 hubstuds are sold by FROR for US$69.

The Toyota axle is slowly evolving into a Dana 60, LOL.

Dave

[plowy]

Another cuase of the studs to break is from being loose there is a actual tension on them about 23 nm correct tension will be in any repair manual

altho i know no one is going to rush out and buy a tension wrench for some axle studs either

[carts]

There are a number of reasons why the studs break on the rear of the toyota. I have sheared 2 sets off on the rear.

The 2 main reasons for the studs shearing is wheel bearing play and the axle flange being out of round.

When the wheel bearings are on there way out and the wheel is a little sloppy, the preload on the axle causes undue stress on the studs eventually causing them to shear off. Tight wheel bearings help this.

2ndly, when people remove the axle to maintain bearings, depending on how you remove the cone washers will ultimately affect the length of time the hub studs will last. By this i mean, a lot of people hit the outside of the axle to remove the cone washers, indenting the axle slightly, causing the countersinking for the conewasher to become slightly out of round. When you bolt everything back together, the cone washers will not seat properly or the axle will seat slightly off the centre of the hub. You will find that if you go to retention the axle studs after 500km, that they will be loose or not as tight as they should be. If left for an extensive timeframe, the axle becomes loose and hammers or manipulates the studs until they shear one by one.

When i worked out what was happening to my studs, after every trip, i would tighten the studs and washers back up, until eventually the cone washers seated themselves properly again. Since then, no problems (been a year). If you tighten them before they loosen themselves off too much, no tensile strength will be lost in the studs, so they wont shear off upon tightening them.

[rock hopper]

i have all the jigs to do a 6 dowls mod to the front and rear of l/cruisers - and front of hi-lux's i do this mod for $70-00 a wheel ....
($70-00 is when u remove axle and hub )

if u want me to do this mod ring to book a time or if your interstate send
your hubs + axle to gympie qld . send pm for address ....

i sell new wheel bearing to suit : $38-00 a kit
Suits Models BJ40 BJ42 BJ73 BJ74 FJ40 FJ45 FJ55 FJ60 FJ62 FJ73 FJ75 FJ80 FZJ75 FZJ80 HDJ80 HJ45 HJ47 HJ60 HJ61 HJ75 HZJ75 HZJ78 HZJ79 HZJ80 LJ70 LN106 LN107 LN111 LN130 LN46 LN60 LN61 LN65 PZJ73 RJ70 RN105 RN106 RN110 RN130 RN36 RN46 VZN130 YN130 YN60 YN63 YN65 YN67

i can also sell new hubs with this 6 dowel mod for :
front :HUB ASSMBLY FRONT HZJ75 (will suit 40# 60# 75# with disk brakes) inc wheel bearings .
Suits Models FJ70 FJ75 FZJ75 HZJ70 HZJ73 HZJ75 LJ70 PZJ70 RJ70
with 6 dowel mod $195-00 ea new without mod $170-00ea

rear : HUB REAR AXLE 7/75- 1/90
Suits Models BJ40 BJ42 BJ73 BJ74 FJ40 FJ45 FJ55 FJ60 FJ62 FJ73 FJ75 HJ45 HJ47 HJ60 HJ61 HJ75 $170-00 ea new without mod $146-00 ea

rear 2/1990 on>: HUB REAR AXLE HZJ75 includes wheel bearings
Suits Models FJ75 FZJ75 HZJ75 PZJ73
with 6 dowel mod $190-00 ea new without mod $165-00 ea
i can also sell new axles that can be sold with the mod ......
pm details for price on new axles


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[simsy]

4wd monthly did this mod in thier mag just recently. if you look on their web forum a guy named graham does a contents page for tech tips which tells which issue it's in