Driveshaft removal - 98 Ex. OHV 4WD

[masospaghetti]

The rear output shaft seal on my transfer case is leaking and I am trying to remove the driveshaft to change it. I'm having trouble breaking the four 12mm 12-pt bolts loose at the front of the shaft. I've tried an electric impact that claims 420-ft-lbs of torque with no success (it's worked on removing axle nuts). This was after I heated up the bolts and used Kroil penetrating oil.

Any tips here?

Thanks all...it's a 98 Explorer, 4.0 OHV, 4WD with 200k miles.

 

[drbenz]

Take a flat tip drift pin about the size of the bolt head and long enough to hold easily and hit it like you were mad at the bolt with a medium size hammer. That will rattle the bolt enough to make it easier to break free. (This can be a hard thing to judge, you have to hit it hard enough to actually shock the threads but not enough to bend the flange, hit it straight enough not to mess up the bolt so a wrench will not fit on it.)

 

[masospaghetti]

Can you clarify? Where am I hammering? Also, I've rattled the bolts around a fair bit using the impact already.

What I don't understand is that there are multiple threads of people removing these with a "12mm combination wrench". I can't believe this considering I can't even remove them with a powerful impact wrench.

 

[corkey]

if they get that stuck i put the wrench on the bolt and than smack the top of the bolt with a hammer as i try to turn it,,
other option i have done before is get new bolts and grind the heads off the old ones,,

 

[drbenz]

Can you clarify? Where am I hammering? Also, I've rattled the bolts around a fair bit using the impact already.

What I don't understand is that there are multiple threads of people removing these with a "12mm combination wrench". I can't believe this considering I can't even remove them with a powerful impact wrench.

You are wanting to hit the top of the bolt head without hitting the sides where the flats are so as not to make it impossible to put a wrench on the bolt afterwards. As to the other part of the problem is that the the bolt turns as you are hitting it with the impact so you lose some of the hitting force. If you have a GOOD quality box end wrench (as in it fits tightly and won't spring open) you can use a piece of pipe or whatever as a cheater pipe to put some extra power on it. Again the problem of stopping the driveshaft from turning is there so put it in park (the hammers in the impact only turn the socket a fraction of an inch, an end wrench has a lot more motion if you don't slip off).

 

[masospaghetti]

Okay, I can try that. It's a 5-speed manual trans though, I'll try setting the parking brake and putting it into gear, hopefully that will keep the driveshaft from rotating.

 

[drbenz]

If necessary put something under the rear wheels or even lower the back end of the truck so the wheels touch the ground long enough to break the bolts loose.

 

[imp]

Worked for me: Good, sturdy 12-point box end wrench, positioned where you can get at it best, hit the end of the wrench (in the right direction!) using a fairly heavy rubber mallet, instead of a metallic hammer. Metal on metal bounces, but the rubber indents itself around the wrench, delivering better, less "slippy" force. imp

 

[RomeovilleIL]

If I recall correctly those bolts have red loctite on the last 1/4" of thread from the factory. I believe the breaking strength is somewhere around 550-600 foot pounds and 400 degrees so your impact doesn't put out enough torque to break them. More often than not I've found a steady pull with long handled wrench works better on tight glued bolts anyway. Once you get the loctite to break, the bolts will turn out. You could try a cheater pipe on your ratchet but it may break from the torque so its recommended to get a dedicated breaker bar at least 18". Autozone has a decent 1/2" drive 24" bar for $20.

 

[snoranger]

Yup, lock-tite.

I've always found it easier to hang a 12mm wrench on it. Slide halfway out from under the truck. Put my foot on the wrench and push. If you need more leverage, hold onto the frame. Never came across one that wont budge that way.

 

[masospaghetti]

Thanks everyone for the tips, I got it to break loose by setting the parking brake, putting it in gear, and cranking down on it with a breaker bar. With some extensions, I could fit a socket on it.

I replaced the seal only to note that there's play in my transfer case output shaft. Looks like that'll be the next project...

 

[jamie3529gq]

helpful tip

once again, helpful info here. I am having the same problem today, my impact running at 130PSI won't budge these driveshaft bolts. Gonna try the wrench and foot idea....

 

[bill06447]

Heat is the best way to free Loc Tite of it's grip without destroying the fastener.

Bill

 

[jamie3529gq]

a 12" breaker bar and my foot worked fine. worst part is climbing in and out from under the truck to keep putting the tranny in neutral or park. I am too old for that!! mama was busy in the house or I would have solicited her help.

big pipe wrench helped to turn the driveshaft to bring the upper two bolts around to the bottom.

I took the front bolts out first, and i forgot to leave a couple bolts in. Then I scratched my head a bit wondering how to hold the rear wheels from turning taking the rear bolts out. Then my brain dropped back into gear - I put a couple bolts back in the front and used the parking catch....

 

[bill06447]

The day you snap off that LocTit-ed 1/4-20 lock bolt that holds the differential spider gear shaft in, is the day you realize a big breaker bar isn't always the answer....ask me how I know