37’s on a Dana 30?

Discussion about deep snow wheeling, vehicle builds, trip reports, etc
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MTWheeler
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37’s on a Dana 30?

Post by MTWheeler »

I’ve been running 35x12.50’s on my CJ5 with good results over the past few seasons, but I’ve recently found a used set of 37x14.50/15 Toyo MT 6 plys for sale for $200. The tread is fair and I thought it would be a perfect set of tires to experiment with a tire groover and have as a ‘snow-only’ set. I guess my question is how many people have run 37’s on a front Dana 30? It’s a stock axle right now, but I have plans for a truss and some RCV shafts in the future. The rear is a boat anchor AMC 20, but it has one piece chromoly shafts, so it should hold up fine.
1977 CJ5 - main family trail rig (work in progress…)
1948 CJ2A
1942 MB
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Re: 37’s on a Dana 30?

Post by Nobody »

A dana 30 isn't ideal, but with some common sense you can get away with it. If you are familiar with SnowBatman99 on youtube, I believe he's running the Cherokee dana 30's front and rear (rear steer) with 38's. I think those Dana 30's have bigger axle shafts and the larger 5-760x u-joints found in most Dana 44's. I think he does break now and again though.

On my V8 Bronco II I got way with running the stock 7.5" rear with 36's for quite awhile. It did eventually break a bearing cap and strip the ring and pinion though. One of the guys i wheel with sometimes had a samurai with stock axles on 35's. He has to be careful to limit wheel hop.

I think the fact that you've been fine with 35's means you know how to drive with some common sense, so you could probably get away with 37's too. Personally, I'd probably throw on the 37's and start looking for a Dana 44.
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MTWheeler
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Re: 37’s on a Dana 30?

Post by MTWheeler »

That was my thoughts as well. The only issue I kinda have with upgrading to a 44, is they all seem to be a minimum of 58” wms to wms. I’d really love to keep my factory width of 54”. Keeping it on the narrow side sure frees up options out on the trail compared to the full width guys. I could always figure out how to cut one down, but it’d be nice to have a straight swap. I figured if I upgraded the shafts and trussed the housing, the weak point would be the R&P at that point.

Like I said, these 37’s would be strictly snow tires only. If they even work, might not even work! But for $200, figured it would be worth a shot, should be a game changer over the 35’s!
1977 CJ5 - main family trail rig (work in progress…)
1948 CJ2A
1942 MB
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Re: 37’s on a Dana 30?

Post by Nobody »

Yeah, you typically would cut down just the long side. It's not too difficult. Grind the weld on the inner C, pop it off, cut the tube, weld the C back on. If it's not in your wheelhouse, see if there is anyone in your area that does it. The OEM Dana 44 stuff should be better than aftermarket Dana 30 stuff. You also have to consider the smaller balljoints or kingpins on the dana 30. The larger tires will wear that stuff out much faster. It's all the same stuff we have to deal with in the Early Bronco world. The earlier years came with Dana 30's.
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MTWheeler
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Re: 37’s on a Dana 30?

Post by MTWheeler »

Think I’ll try to make a deal on those tires, and just go from there! Does good in the snow with the 35’s, but 37s gotta be that much better right?? Wanted to try to groove a set for snow only, and this would be a cheaper way to get my foot in the door. The axles would be my only concern, it has a mild 304 that make decent torque but nothing too crazy.
1977 CJ5 - main family trail rig (work in progress…)
1948 CJ2A
1942 MB
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Re: 37’s on a Dana 30?

Post by Seventee »

The problem with the Bronco Dana 30 was the weak ring and pinion, and there's no upgrade to fix that. If that's also true for the Jeep version I wouldn't bother upgrading the rest of the axle with RCVs etc. It will be money wasted.
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MTWheeler
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Re: 37’s on a Dana 30?

Post by MTWheeler »

The other day, I was running some errands in town. I happen to drive past my local Harley shop, and they also sell those Mahindra Roxor’s. Got my wheels turning, and a quick google search shows they come with D44’s. 53ish” wide, AND a passenger side diff. $1400 for a brand new one. :D
1977 CJ5 - main family trail rig (work in progress…)
1948 CJ2A
1942 MB
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