A Guide: Replacing toyota 3rd member studs with 3/8 bolts
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A Guide: Replacing toyota 3rd member studs with 3/8 bolts
i am reposting this from my build thread into the tech forum here...i figure if one person is helped by it, then its worth the trouble...cheers
it is common for the stock studs to pull out of the housing thus wreaking havoc on just about every component of your driveline from the pinion back...repleace those bitches with 3/8 grade 8 bolts, lock washers, nuts for extra strength. The original mod calls for fine threaded bolts...well, as luck would have it, no one carries fine thread so i used coarse thread and i dont see why it would make any difference....on to the edu...
Time:
2 hours
needed:
ten 3/8 x 1.5" grade 8 bolts
ten locking washers
ten 3/8 nuts
basic hand tools
grinder w/ cutoff disc and grinding disc
welder
nice to have but not necessary:
stud extractor / installer
hot tank for cleaning all the shit out of the housings (oil and grease does burn :o )
stock stud beside a 3/8 bolt
stock vs 3/8
first remove the old and busted studs (i highly suggest using a stud extractor / installer as it makes short work of them).
chock a 3/8ths bit in the drill
drill them bitches out!! do take care to actually drill straight through the holes
put them bitches in!!
this is where i took a break for the night to continue in the shop back home...all of this can be done with access to a welder and a grinder...which i dont have locally.
next cut off the paper cover for the diff...its easiest to weld the bolts in from the backside of the housing...
clean up the holes with a grinder and prep them for welding...be sure to get all the grease out of the housing as it burns readily (ask me how i know )
this tab was in the way and would not let the bolt sit all the way down on the housing...a grinder makes short work of it....
tab clearenced....
here is where you need to tack the bolts in place. do be sure to have a flat edge of the bolt towards the inside so the 3rd will clear it!!!!!
i missed some pics FYI....
take the third housing and drill it out using a 13/32 drill bit...that extra space for the 3/8 bolt makes putting the third in alot easier when you are done!!!
bolt up the third and burn those bolts in!!!
third removed and bolts welded in...
replace paper cover and weld it back on...
shitty pic of the welds
third bolted on and cover welded back on...all done!!!
definitely beefier than the stock stuff and well worth the time it takes...
all told i have about 2 hours of work into this not including running around and getting needed items like cutoff disc, grinding disc, bolts, etc.
it is common for the stock studs to pull out of the housing thus wreaking havoc on just about every component of your driveline from the pinion back...repleace those bitches with 3/8 grade 8 bolts, lock washers, nuts for extra strength. The original mod calls for fine threaded bolts...well, as luck would have it, no one carries fine thread so i used coarse thread and i dont see why it would make any difference....on to the edu...
Time:
2 hours
needed:
ten 3/8 x 1.5" grade 8 bolts
ten locking washers
ten 3/8 nuts
basic hand tools
grinder w/ cutoff disc and grinding disc
welder
nice to have but not necessary:
stud extractor / installer
hot tank for cleaning all the shit out of the housings (oil and grease does burn :o )
stock stud beside a 3/8 bolt
stock vs 3/8
first remove the old and busted studs (i highly suggest using a stud extractor / installer as it makes short work of them).
chock a 3/8ths bit in the drill
drill them bitches out!! do take care to actually drill straight through the holes
put them bitches in!!
this is where i took a break for the night to continue in the shop back home...all of this can be done with access to a welder and a grinder...which i dont have locally.
next cut off the paper cover for the diff...its easiest to weld the bolts in from the backside of the housing...
clean up the holes with a grinder and prep them for welding...be sure to get all the grease out of the housing as it burns readily (ask me how i know )
this tab was in the way and would not let the bolt sit all the way down on the housing...a grinder makes short work of it....
tab clearenced....
here is where you need to tack the bolts in place. do be sure to have a flat edge of the bolt towards the inside so the 3rd will clear it!!!!!
i missed some pics FYI....
take the third housing and drill it out using a 13/32 drill bit...that extra space for the 3/8 bolt makes putting the third in alot easier when you are done!!!
bolt up the third and burn those bolts in!!!
third removed and bolts welded in...
replace paper cover and weld it back on...
shitty pic of the welds
third bolted on and cover welded back on...all done!!!
definitely beefier than the stock stuff and well worth the time it takes...
all told i have about 2 hours of work into this not including running around and getting needed items like cutoff disc, grinding disc, bolts, etc.
- yotacowboy
- Posts: 581
- Joined: Thu Dec 16, 2004 6:28 am
- Location: b'burg
- Contact:
to add some more tech: generally fine pitch threaded studs and bolts are used where there is a need for fairly specific torque values, among other things... to add even more tech: you can dig around on the web and find the torque values toyota spec'd on those studs, calculate the clamp force, then back calculate what the coarse threaded bolts need to be tightened to... or just put a glob of loc-tite on them... i'd vote for the loc-tite.
'91 Reg. Cab Yota DD: DOA 22re RV, .060 over,270 cam,ported,Thorley Tri-Y,2.25 cat,Flowey 40,SAS'd,Locked,Longed,Pig'd,Bumpered,Slidered,Sky wide axle,5.29's,Duals,Sky Tcase skid,37" Iroks,2.5" BS blk steelies,Allpro Hy-steer,HighAngle D-lines
i did not know that torque values were specific to fine thread bolts...yotacowboy wrote:to add some more tech: generally fine pitch threaded studs and bolts are used where there is a need for fairly specific torque values, among other things... to add even more tech: you can dig around on the web and find the torque values toyota spec'd on those studs, calculate the clamp force, then back calculate what the coarse threaded bolts need to be tightened to... or just put a glob of loc-tite on them... i'd vote for the loc-tite.
learn something new everyday
its specific to a lot more than pitch thread too. spent a whole chunk of mechanical design class on bolted joints.... look forward to it.
basically fine pitch requires less torque to produce the same clamping force because the finer pitch has more mechanical advantage- think force required to go up a steep hill vs a less steep hill.
for a rough conversion, multiply the specified torque for fine thread * coarse thread pitch and divide by fine thread pitch. (pitch = distance between threads). I think that should get you close.
basically fine pitch requires less torque to produce the same clamping force because the finer pitch has more mechanical advantage- think force required to go up a steep hill vs a less steep hill.
for a rough conversion, multiply the specified torque for fine thread * coarse thread pitch and divide by fine thread pitch. (pitch = distance between threads). I think that should get you close.
The Rescue Ranger: in pieces and scattered about the yard.
thanks....i wasnt about to look up some 3 page equation for the conversion :oPiney wrote:its specific to a lot more than pitch thread too. spent a whole chunk of mechanical design class on bolted joints.... look forward to it.
basically fine pitch requires less torque to produce the same clamping force because the finer pitch has more mechanical advantage- think force required to go up a steep hill vs a less steep hill.
for a rough conversion, multiply the specified torque for fine thread * coarse thread pitch and divide by fine thread pitch. (pitch = distance between threads). I think that should get you close.
but i will definitely use the simple one you stated....plus a dab of locktite