HOWTO - Use Some ABS Pipe to Pull Front Cab Mounts
There are several threads here on FTE about people who have replaced the cab mounts on their trucks. This isn't a comprehensive how-to, but a simple tip that can help get the front cab mounts off.
As you can see in the following diagram, there are six mounts in total - two underneath the radiator core support, and four at the four corners of the cab. This tip is only for the front two cab mounts. It might also work for the core support mounts but I didn't need to.
The front two cab bolts are located about where your feet go as you’re driving, underneath some inspection covers.
On all four corners, the bolts extend down through the floor of the cab, through the rubber mounts, and thread onto a nut/washer combo underneath the cab. I soaked the bolts/nuts in some penetrating oil and had no problem removing these bolts.
What is the problem is that the rubber mounts from the factory also have these steel tube inserts inside them, that seem to rust together and make it nearly impossible to break the mount off the perch. For me, removing the bolts was the easy part, removing the old mounts is the bear.
It is hard to see these "tubes" in the diagram below, but if you look at view "W" it is the "Upper absorber assembly" and the "lower retainer" that are press fit together. But the lower retainer is threaded, and this is what we can use to our advantage.
The hard way is to loosen the stock bolt from the top but don’t remove it completely. Leave it threaded into the bottom retainer, but sticking up above the floor an inch or so (the stock bolt is plenty long enough for this). Now wham on that bolt with all your might using a BFH and if the gods are smiling, you will eventually knock that bottom retainer off.
The easier way is to build some kind of puller to pull that bottom bushing off. I was able to do this for the front mounts, which is what I am going to share in this thread. I couldn't figure out a way to do so for the rear mounts, on those I had to use the big hammer and much swearing.
The front cab mounts are very easy to access underneath the cab. You will easily see them at the front corners, attached to perches riveted to the frame. The bottom retainer piece is what we want to pop off. Here’s the puller tool I made.
Go to Home Depot and get yourself the following two items from the ABS pipe section (photo below). Total cost about 5 bucks. You might also want to get some thick washers from the hardware section.
Screw that plug into the fitting and drill yourself a 7/16 hole right in the top of it. You might want to put some lube on the threads of that plug to get that fitting to screw in, I also used a strap wrench on the female adapter and a large crescent wrench on the plug to tighten it.
Now this is your puller. It should fit right over the front cab bushing. The fit will be tight between the ABS piece and the metal frame perch but once you start tightening things up it will snug in.
Put some lube on the threads of your stock bolt, and thread it up through your ABS "puller", up into the bottom cab bushing. Use some thick washers under the head of the bolt to spread the load a bit. Now just get your socket wrench and start cranking that bolt tight.
I was pretty sure my ABS pipe would crack or shatter before I got the mount pulled, but amazingly, although I put a great deal of muscle into it, the puller stood up to the test and eventually I got a loud POP! and my bushing had separated.
The other thing I figured that would happen, is that instead of the bolt threading itself up into the bushing, that eventually the bushing would just start to spin. But that didn't happen to me, I think the tension of the bolt being tightened keeps the retainer from spinning.
I used my puller on both front mounts. After the second mount was off I could see the black ABS plastic turning white in a couple places from stress, but it didn't break. Even if worse came to worst, I figured I could always build a second puller for five more bucks. Eventually this should get your front mounts off.
Now – I sure wish I had a good trick to share for the rear mounts. On my truck the bushings were recessed up into a crossmember and there was no way to get this puller tool up in there. I finally was able to get them out with the brute force beating method.
More on bushing removal in the next post…
3" diameter ABS pipe pieces to construct a puller.
Puller on the front mount, and bolted on.
Start cranking with your socket. Notice the big washers to spread the load. I also lubed the washers in addition to the bolt threads before I began.
Once you get the lower bushing-half broken free, the rest is mostly easy. Do one side at a time (left or right). Remove the bolts completely from the side you are working on, and loosen them on the opposite side but leave them in so the cab doesn't slide off.
Jack up the cab at the corner you're working on, just enough to slide out the upper half of the bushing, and slide your new one in. Lower the cab back down. Bolt er' back up.
Now the one thing I noticed, is that when you start jacking one corner of your cab, a lot of squeaking and other ominous noises begins to ensue, and I could see the entire cab twisting slightly, and it gets worse the higher you jack.
The stock bushings you are removing have this metal insert that sticks down through the perches. You have to jack your cab up pretty high in order to clear this metal piece. I decided to cut it off with my Dremel tool so I wouldn't have to jack as much, and twist my cab as much. This takes more time but the result is you barely have to jack the cab at all to slip out the stock mount. The replacement mounts seemed even shorter than my old ones so they slipped right in.
Metal piece of the top-half of the bushing sticks down through the perch.
Grind that bad boy off.
Jack the cab - unless you have a massive jack, you will probably have to use some wood to reach the bottom of the cab.