New Member with leaf spring question
#1
Newbie
Thread Starter
Join Date: Nov 2016
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
New Member with leaf spring question
Hey All- I've been lurking here for a while now and I have a quick question so I figured I'd introduce myself. Here are the stats on my rig:
1997 / 4.0 / 2WD / AW4 / Chrysler 8.25 / 165,000 miles
Daily driver / Occasional camper
Good shape... No Rust. I've had it for a little over a year and have done a few odds and ends but nothing major. It currently doesn't leak anything. I say currently because I know that's temporary! It had a fresh rear main seal and new oil pan gasket when I bought it and i recently did the valve cover gasket and oil filter adapter. I also did the Putco headlight harness upgrade. No new bulbs yet but the harness made a big difference.
Anyway on to my question. I'm getting ready to change the leaf springs... I have read up on the front bolt/bushing issue and I have all the goodies should it become a problem. My question is about the application of heat to that bolt.
If I need to apply heat... where does the heat get applied to? I'm assuming you heat up that captured nut to expand it but how do you get to it? There's the hole in the unibody that I've been using to hose the nut down with PB blaster but it's not exactly a straight shot for a torch. Plus there's all the PB blaster in there. Will that catch on fire? Or do you heat up the head of the bolt. That seems counterproductive but I'm no expert.
TLDR: What part of the front leaf spring bolt do you heat? The head of the bolt or the captured nut?
Thanks guys.
1997 / 4.0 / 2WD / AW4 / Chrysler 8.25 / 165,000 miles
Daily driver / Occasional camper
Good shape... No Rust. I've had it for a little over a year and have done a few odds and ends but nothing major. It currently doesn't leak anything. I say currently because I know that's temporary! It had a fresh rear main seal and new oil pan gasket when I bought it and i recently did the valve cover gasket and oil filter adapter. I also did the Putco headlight harness upgrade. No new bulbs yet but the harness made a big difference.
Anyway on to my question. I'm getting ready to change the leaf springs... I have read up on the front bolt/bushing issue and I have all the goodies should it become a problem. My question is about the application of heat to that bolt.
If I need to apply heat... where does the heat get applied to? I'm assuming you heat up that captured nut to expand it but how do you get to it? There's the hole in the unibody that I've been using to hose the nut down with PB blaster but it's not exactly a straight shot for a torch. Plus there's all the PB blaster in there. Will that catch on fire? Or do you heat up the head of the bolt. That seems counterproductive but I'm no expert.
TLDR: What part of the front leaf spring bolt do you heat? The head of the bolt or the captured nut?
Thanks guys.
#2
CF Veteran
Ideally you would want to apply the heat to the nut but that's not very possible. My idea is to drill a 1/8 inch hole in the pocket around the nut and squirt some PB in there. That hole in the frame is just the end of the bolt sticking through. I've sprayed in there too but it's no guarantee that enough of the PB will wick up into the nut
#3
CF Veteran
Join Date: Jan 2012
Location: Ocean County, NJ
Posts: 2,208
Likes: 0
Received 3 Likes
on
3 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L
Slowly apply heat to the head of the bolt. You cannot get to the captured nut. You want heat to travel through the entire bolt, not just the head. If it starts to glow, remove heat until it is no longer glowing, reapply heat. Do this until the bolt is hot then try removing said bolt. I highly recommend using a 1/2 impact gun. If this isn't possible, be very careful with a breaker bar. I suggest attempting to "work" the bolt in and out to break the rust up as much as possible. DO NOT just go *****-to-the-wall trying to back this bolt out. Be patient and turn the bolt a little at a time in each direction. If it starts freeing up, continue working it. A little out, a little in. A little more out, a little in. Don't allow the bolt to fully cool. Keep it warm/hot
#5
Newbie
Thread Starter
Join Date: Nov 2016
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Got the leafs in today. Went ahead and hit those bolts with some heat before trying to loosen them. Got them good and hot and they came right out. Getting the bolts back in to the new springs was WAY Harder than getting them out. Probably would have been easy with a helper but I was solo on this one. Took about 5 hours from jacking it up to drinking a victory beer after clean up.
#7
CF Veteran
5 Hours! You made great time. Mine took 1.5 days. (1.48 days to get them out, and about 20 minutes to put the new ones in!)