Meanwhile in Florida

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Tue 23 Mar 2021 23:11
Meanwhile in Florida - Metropolis.

Whoops! Jeep Wrangler Engine Explodes After Owner Tows Vehicle In Gear And Revs It To 50,000 RPM

www.thedrive.com/news/39794/rv-driver-annihilates-...w

Edited by Xileno on 24/03/2021 at 19:09

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Wed 24 Mar 2021 09:03
Meanwhile in Florida - mcb100
The video isn’t viewable unless you sign into Jalopnik.
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Wed 24 Mar 2021 15:37
Meanwhile in Florida - Heidfirst

nm

Edited by Heidfirst on 24/03/2021 at 15:38

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Wed 24 Mar 2021 16:52
Meanwhile in Florida - bathtub tom

I've read about this elsewhere. Apparently the recommendation for towing is they should be in drive, with 4WD selected. This means the pumps are able to circulate fluid. This one was unfortunately in low ratio and towed at 55MPH!

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Wed 24 Mar 2021 17:01
Meanwhile in Florida - Metropolis.
Yes, the link is dodgey for me as well sorry, it worked better on Facebook. Apparently it was left in 1st gear low range and revved itself (maybe engine nor even running?) to the point of exploding.

I don’t really understand this, (advice to keep it in drive), I had assumed it would be better to put the gearbox in neutral, transfer case in neutral and engine off, assuming the vehicle is permanent 4wd like a Land Rover is. But even Land Rover only recommend very slow flat towing on automatics, which I never understood either, if there is no connection to the wheels I cant see the difference but I guess I have a knowledge gap!

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Wed 24 Mar 2021 17:17
Meanwhile in Florida - skidpan

This one was unfortunately in low ratio and towed at 55MPH!

50,000 rpm at 55 mph would be under 1mph /1000 rpm. No 4 x 4 in my experience has such a low ratio. A Land Rover from the late 70's had a low first of about 2 mph/1000 rpm.

Does a Jeep have such a pointless low ratio first? The Land Rovers we had a work were most driven in low 2nd on site (lower than high ratio first) even in extreme conditions.

I would have expected the Jeep engine to explode before 50,000 rpm. the pressures inside the engine must have been tremendous.

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Wed 24 Mar 2021 17:24
Meanwhile in Florida - kiss (keep it simple)

Assuming engine braking would have occurred I can't see how the vehicle could have been towed at all. Surely the wheels would be virtually locked up. Or am I missing something?

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Wed 24 Mar 2021 17:48
Meanwhile in Florida - Metropolis.
“ Does a Jeep have such a pointless low ratio first?”

It is called a crawler gear, used for going up steep rock faces like in Moab, Utah.
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Wed 24 Mar 2021 17:58
Meanwhile in Florida - skidpan
“ Does a Jeep have such a pointless low ratio first?” It is called a crawler gear, used for going up steep rock faces like in Moab, Utah.

Landrovers had a crawler gear, we used it on construction sites and doing surveys out in the Welsh outback. Probably not as extreme as Utah (but wetter) and one particular track was probably a muddy 1 in 3 and it did it in low 2nd with no issues (except for our heart rate).

That Landrover had travelled to Afghanistan overland in the 70's. Ran low on oil and it just kept going (did not do it a lot of good, needed an engine rebuild when back in the UK).

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Wed 24 Mar 2021 17:44
Meanwhile in Florida - Metropolis.
From the article:

As you can see in the clip, the crankshaft is broken, the block and pan are in pieces, there’s no flywheel or clutch kit to be found, the catalytic converter is destroyed, the bell housing is toast, the manual transmission input shaft has been sheared, and — though it’s hard to tell — I’m fairly sure the passenger’s side upper control arm was bent by the flying debris. It’s just a huge mess.


But that’s what happens when you have lots of reciprocating mass moving far faster than it was ever designed to. The Pentastar Upgrade was really only ever meant to consistently rev to roughly 6,600 RPM. With the Rubicon coming stock with a 4.10:1 axle ratio and a 4:1 transfer case low range ratio, and with first gear at 5.13:1, the vehicle’s crawl ratio is 84.13:1. This means the engine spins 84.13 times as fast as the rear wheels do.

If we assume that the RV was towing this Jeep at 60 mph (we don’t really know how fast it was traveling; the shop foreman that The Drive spoke to guessed 55), we can use the fact that the Jeep’s stock 285/70R17 BF Goodrich KO2s are rated to turn 645 revolutions per mile to learn that, at that speed, the vehicle’s tires were spinning at 645 rpm.
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Wed 24 Mar 2021 21:06
Meanwhile in Florida - Metropolis.
I’m just imagining a blissful driver of a massive coach sized RV in his lazy boy chair, cruise control on, TV somewhere near the windscreen just for the driver and air con set just so, massively powered v8 or v10 petrol or diesel engine humming away in the background as it lopes serenely through the Florida panhandle. Meanwhile, the little jeep strapped up behind is revving its nuts off probably showering the cars behind in debris, dont know why but that image just makes me LOL!
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