Changing the front cab mounts on the 1078A1

[Kambaku]

Does anyone have any experience changing the left and right front rubber cab mounts on the 1078A1.

The mounts are the same part numbers as the back center cab latch which I have changed without any problems.

The left and right front mounts tend to deteriorate overtime just like the the rear cab latch mount and since I have the parts I want to change them.

If you raise the cab it's easy to get at the one on the right front. The bolt is captive in the channel on top and you can loosed up the lower nut with a 1 3/16" deep well socket and loosens up the parts. The left one is a little more problematic because you have to work around the steering box and other stuff in the way, but it's not impossible.

However, getting the nuts off and the parts loose is only half the battle. Somehow, it appears that you will have to raise the cab up about an inch or so to slide in the new mount on top, then drop the bolt through. The bottom one is easy. So my question is, does anyone have any experience or tips that they can share to raise the cab up a bit to get at the top mount. Like I said, it likely needs to come up about an inch to slide these in.

Many thanks if you can help...

 

[Suprman]

The repair TM should have a specific procedure. The first variant TM should have it and it should be the same for your A1. Maybe the hydraulic cab raise/lower comes into play for this.
Will

 

[Kambaku]

Thanks for the direction. I found some reference to this procedure in TM-9-2320-365-32-2 Chapter 15. These procedures pretty much describe cab removal which would give you great access to these parts. That should not be required for the replacement, however, I may have missed something. The cab lifting device is easily constructed, but there may be other ways, yet unexplored. If one uses the lifting device, the question I have is what may or may not need to be disconnected to give you the clearance to slip these in. There's a lot of stuff in there! Perhaps someone with experience knows, nonetheless, it appears that it's going to be a little more work than the back one.

 

[Suprman]

I have an A1 paper manual if there is something different I can see if I can find anything else on it. Post some pics when you do it.
Will

 

[Lmtv772]

If I were to do this. And I may have to soon. I would loosen up one side and leave a few turns on the nut. Loosen the other side completely. Lift up the cab with a strap and pallet lift to about an inch , get the bushing out and the new one in.

 

[Kambaku]

Thanks, I'm thinking along those lines too. It would be nice to see the procedure described in the A1 manual, but at this point I don't have it. Access to the nut holding the resilient mount on the right is easy. On the left, I think you need to drop the front skid plate and come up from the bottom with an extension and the 1 3/16" deep well socket. With both nuts off the lower rubber and the big washer comes off and can be replaced, but that won't be enough, because the issue is the top one, that's where all the compression is on these mounts.

 

[Guyfang]

I seem to remember we came up from the bottom to get at the mount bolts. Its been about 5-6 years ago, but i THINK that's how we did it. We lifted the hood up with a crane/lift if you have one its easier.

 

[Suprman]

This one?

 

[Kambaku]

Yes, those are the ones. With it stripped down like that who needs a manual

 

[Johno176]

Here is how I did mine recently. Do one side at a time. With cab fully lowered, remove the lower nut and washer. Then raise cab with air/hydraulic pump or manual pump slowly. When you get about 1/4 of the way up visually check the mount. Because the nut is off, the cab hydraulic cylinder will begin to lift the upper mount surface from the upper isolator. When you get about a half inch separation, you can remove and replace the isolator. Lower the cab back down and reinstall the spacer, lower isolator, washer, and nut. Then repeat for other side.

 

[Keith Knight]

I'll need to do this to my '03 A1 also, as it seems all A1 LMTV's the rubber used doesn't last very well. If you could please share with me where you acquired you body mounts so I can replace mine as well. My rear sway bar bushings were also rotted out and missing all together. I searched and could never find those and resorted to making them my self. But I much prefer not making parts if they are available for purchase.
Thanks

 

[Kambaku]

View attachment M1078A1_cab.latch.pdfView attachment PS Mag FMTV Front Cab Mounts.pdf

First time for me trying to add attachments so if it doesn't come through properly, I'll try again. There should be 3 documents attached. 1) the parts breakdown, 2) a page from PS Magazine calling attention to the front mounts (same part #'s) and 3) a photo of my mount before I changed it. I know it was beyond hope, it's happy now!

The earlier 1078's do not have the rear center rubber cab mounts like I had on my 2008 A1, I think the front are the same.

For the rear, you need two (2) of NSN 5342-01-371-7258 part number 12417622 and, one (1) of NSN 5342-01-371-7973 Part number 12417600.
For the front, (one set for each side) for a total of two (2) of NSN 5342-01-371-5258 and two (2) of NSN 5342-01-371-7973.

Google searches will turn up a number of suppliers, some of which are more than extremely proud of their prices, some are vendors on this site. I found the range to be anywhere in the neighborhood of $18@ to more than $200, yes I'm serious. Some vendors give you the best deal when you are willing to take a quality, e.g., 10, so a group buy, coordinated by someone would work. I am reluctant at this point to post sources on a public form without permission from vendors.

 

[Suprman]

I have the fronts 2 each side they are used but were installed when the truck was rebuilt in late 2012. They will include the nuts and bolts. I may have rears I would have to look. The truck is an 03 A1 so they should be the correct ones.

 

[Kambaku]

I wanted to finalize my report on changing the cab mounts on the 1078A1.

The rear center mount was very easy. Simply pull the bolt and put in a new set of mounts. It was not much more than that.

The front mounts, however, are another matter. However, using suggestions from other's who posted on this thread and experience gained by another member of this great community I got it done.

In a nutshell, if you pull the bottom nuts off the front mounts with a 1 3/16" deep well socket you're half way there, i.e., on the passenger side. I say this because access is easy and all it takes is a bit of muscle to undo that nut [re-install torque specs are 199-243 lb-ft (270-330 N-m)]. As previously posted, you can use the cab's lifting hydraulics to lift the cab enough to pull out the bolt and slide in the new mounts. I pumped the lifting mechanism manually, with the hand pump to do this because I had more control over the process.

The drivers side is a lot more work due to access. I had to pull the front plate to get a long extension in from the bottom to get at the nut, it was tight and some PB Blaster helped. The cab's hydraulics would not lift this side of the cab, perhaps because the actuator arm is on the passengers side and there are other things in the way on the drivers side, e.g., steering box linkage. To lift this side of the cab, I put a hydraulic jack under the vehicle sitting on some cribbing with a block of wood on top of the jack to a suitable spot under the cab where I could get some purchase. I slowly raised the jack and the mount came loose. There is very little room to pull the long bolt out to get at the mount itself, but you can do it. This same procedure was done on two different vehicles so we know it works. Just use sufficient caution during jacking because there are a number of things attached to the cab besides the steering linkage. Again, there is barely enough room to pull out the bolt but it can be done.

 

[Lmtv772]

I am looking for a set of cab mounts.

 

[Kambaku]

See my PM

 

[Kambaku]

Sorry duplicate post. I sent you a PM as stated above.

 

[bikeracer917]

Anyone have a good inexpensive site to purchase the rear mount bushings

 

[Awesomeness]

Anyone have a good inexpensive site to purchase the rear mount bushings

I saw that there are currently 5 left on eBay for $15/ea, under the auction name "FRONT-CAB-SUPPORT-WEAPON-SYSTEM-MOUNT-FOR-M1078-M1083-TRUCK-5342013717973". Probably won't beat that price again. So two people will get a pair, then one poor sole gets only 1, haha.

 

[scottmandu]

I saw that there are currently 5 left on eBay for $15/ea, under the auction name "FRONT-CAB-SUPPORT-WEAPON-SYSTEM-MOUNT-FOR-M1078-M1083-TRUCK-5342013717973". Probably won't beat that price again. So two people will get a pair, then one poor sole gets only 1, haha.

Be aware of the cure date, after about a couple years of age sitting on the shelf the mounts harden and then crack when installed.