When I bought the eff two fiddy, the PO told me that the DieHard Golds had been in it for at least six years and they'd probably need to be replaced. After some starting issues with WMO, bad lift pumps and changed fuel filters, they had cranked their last diesel starter reliably.
Fortunately, thanks to the Oilburners corner of the internet and punkmechanic, I acquired enough knowhow and the actual batteries to pull off this project.
I picked up these bad boys from Justin (punkmechanic) last Sunday:
Here's what one of them looked like compared to the old DieHards:
I decided I wanted the absolute biggest and best wire I could find. I went to a local welding supply shop and picked up 20 feet of 4/0 welding lead:
The way the battery trays are mounted doesn't leave enough room for group 31 batteries width-wise. There's a wiring harness in the way on the outboard side of both batteries that needs to be rerouted. In order to do this, I removed the tray (the driver's side is the only one pictured; the passenger side procedure is exactly the same):
I then cut off the plastic clips that secure the harness to the core support and finessed them into place below where the modified tray would sit. You can just see the harness in the lower right-hand corner of the above picture.
Here's what the battery tray looked like:
The tray is just slightly too narrow to accommodate these semi-truck monsters. In order to have the group 31s fit in the stock tray, I cut the inboard edge with a grinder and used a large crescent wrench to barely bend the tabs out. Now they fit side to side:
And, as you can see the new batteries fit front to back with room to spare. However, they are noticeably taller than group 65s:
Not a lot of room.
I order to be 100% sure that the positive lug on the new batteries wouldn't be jumping up into the hood and causing all sorts of problems, I stopped by NAPA and bought some battery hold-downs. Fortunately, the stock battery trays have holes in them for hold-downs, they're just not used in our application.
After I modified the drivers side tray, I made the ground cable and the cable that connects the two batteries together. Not very complicated, it just required pulling out the old cable, measuring it, cutting the new 4/0 to length and crimping on the lugs. Here's what I used for the crimping:
They're a set of Greenlee adjustable crimpers you can use for wire from size 8 to 4/0. Fortunately, I work in the electrical industry and was able to borrow these for the weekend from one of my coworkers. I'm pretty certain I wouldn't want to shell out the coin required to buy one of these.
After I made up the cable that connects the two batteries, I pulled the passenger battery tray out and made the same modifications to it as the driver side tray. I also re-routed the wiring harness in the same way.
The ground cable on the passenger side battery was relatively simple to make. The hardest cable to make was the passenger battery-to-starter cable. I got it cut, crimped and routed correctly and ended up reusing the bracket that holds it in place from the engine block. I messed up on the location of that and ended up having very little extra cable to bolt onto the passenger battery. I'll get that straightened out at another time.
Here's one of the lugs before I crimped it on the wire:
That was the only lug I had to bend because of space concerns. It was the one that bolted to the starter. You can see some gray goo coming out of the bottom of the lug. That's Noalox, a corrosion inhibitor. I'm hoping it will prevent corrosion of the fine stranded copper for as long as I own the truck. I also used heatshrink over the lugs once I crimped them on. I think it looks pretty good.
Here's the before:
And here's the after:
So, all in all, it was time well spent. It was a job done right and I don't think I'll be having any battery problems for awhile.
Plus, I've got 2000 CCAs under the hood.
Fortunately, thanks to the Oilburners corner of the internet and punkmechanic, I acquired enough knowhow and the actual batteries to pull off this project.
I picked up these bad boys from Justin (punkmechanic) last Sunday:
You must be registered for see images
Here's what one of them looked like compared to the old DieHards:
You must be registered for see images
I decided I wanted the absolute biggest and best wire I could find. I went to a local welding supply shop and picked up 20 feet of 4/0 welding lead:
You must be registered for see images
The way the battery trays are mounted doesn't leave enough room for group 31 batteries width-wise. There's a wiring harness in the way on the outboard side of both batteries that needs to be rerouted. In order to do this, I removed the tray (the driver's side is the only one pictured; the passenger side procedure is exactly the same):
You must be registered for see images
I then cut off the plastic clips that secure the harness to the core support and finessed them into place below where the modified tray would sit. You can just see the harness in the lower right-hand corner of the above picture.
Here's what the battery tray looked like:
You must be registered for see images
The tray is just slightly too narrow to accommodate these semi-truck monsters. In order to have the group 31s fit in the stock tray, I cut the inboard edge with a grinder and used a large crescent wrench to barely bend the tabs out. Now they fit side to side:
You must be registered for see images
And, as you can see the new batteries fit front to back with room to spare. However, they are noticeably taller than group 65s:
You must be registered for see images
Not a lot of room.
I order to be 100% sure that the positive lug on the new batteries wouldn't be jumping up into the hood and causing all sorts of problems, I stopped by NAPA and bought some battery hold-downs. Fortunately, the stock battery trays have holes in them for hold-downs, they're just not used in our application. After I modified the drivers side tray, I made the ground cable and the cable that connects the two batteries together. Not very complicated, it just required pulling out the old cable, measuring it, cutting the new 4/0 to length and crimping on the lugs. Here's what I used for the crimping:
You must be registered for see images
They're a set of Greenlee adjustable crimpers you can use for wire from size 8 to 4/0. Fortunately, I work in the electrical industry and was able to borrow these for the weekend from one of my coworkers. I'm pretty certain I wouldn't want to shell out the coin required to buy one of these.
After I made up the cable that connects the two batteries, I pulled the passenger battery tray out and made the same modifications to it as the driver side tray. I also re-routed the wiring harness in the same way.
The ground cable on the passenger side battery was relatively simple to make. The hardest cable to make was the passenger battery-to-starter cable. I got it cut, crimped and routed correctly and ended up reusing the bracket that holds it in place from the engine block. I messed up on the location of that and ended up having very little extra cable to bolt onto the passenger battery. I'll get that straightened out at another time.
Here's one of the lugs before I crimped it on the wire:
You must be registered for see images
That was the only lug I had to bend because of space concerns. It was the one that bolted to the starter. You can see some gray goo coming out of the bottom of the lug. That's Noalox, a corrosion inhibitor. I'm hoping it will prevent corrosion of the fine stranded copper for as long as I own the truck. I also used heatshrink over the lugs once I crimped them on. I think it looks pretty good.
Here's the before:
You must be registered for see images
And here's the after:
You must be registered for see images
So, all in all, it was time well spent. It was a job done right and I don't think I'll be having any battery problems for awhile.
Plus, I've got 2000 CCAs under the hood.
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