Gears ? For towing

[CrazyCooter]

I believe Rory was also saying that it was an optimal combination of tooth size and pinion/ring overall size.

Then factor in the gear multiplication in the t-case that severely loads the driveline if the R&P set is taller than ideal.

Guys with the Samurais were doing 6:1 t-case gears becuase you could get away without doing a R&P swap do to the high range reduction.....However you quickly found the "other" weak links like T-case mounts and drivelines. I liked to do a 4.57 in the axles and either a 4.16 or 4.89 t-case to split the loads up a little bit.

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[Blade1668]

The difference between 3.73 and 4.10 is 9.1%. The difference between 7th and 8th is 20.1%.

I really think the issue here is where your 3.6 makes it's tq high in the powerband....... That said, with that narrow tq band, you could find yourself in between gears and that 9.1% change would help you out with keeping the rpm's lower than current under a load.

I'd be more inclined to do to 4.56's (18.2%) especially since you have a slightly taller tire and frequently tow. If she currently likes driving in 7th gear while unloaded, the 4.56 would be much the same in 8th.

Cost will likely range from $1600 at the economy shops that don't replace bearings to over $3K at a quality shop that insists on doing the job the best way possible and provides a warranty to back the job up.

Only way I would be doing a gear change "if me" 3:55 or 3:73 would be to at least 4:56 ratio or maybe 4:88 otherwise I don't think it's "worth the squeeze" I've replied with this in a few different threads. Money wise too, going from 3:73 to 4:10 not a logical "not much of a impact other than empty wallet" now 4:56 or 4:88 yes. A significant change especially since most people will increase their tire size.
To add I've got 2 Jeeps with 3:54/3:55, one with 3:73 "stock in LJ", 4:56 in XJ and 4:10 in JT. Not likely that I would re-gear my JT with 4:56 or 4:88 unless I happened to "win" a full set of aftermarket axles.

 

[Gvsukids]

The 3.6 is a high strung engine, so best to rev it higher and reduce load than to lug under heavy and rattle it apart?

Even my diesel at work likes to run at a high rev.

 

[ShadowsPapa]

Even my diesel at work likes to run at a high rev.

That's sure different than the diesels I used to own - 2700 was a top RPM. (but they were unstoppable)

 

[CrazyCooter]

Even my diesel at work likes to run at a high rev.

In comparison to what? My Cat C12 redlined at 2100 and Cummins 5.9 at 3200rpm, but they layed down way before then.

The Ecodiesel seems to come to life at about 1900 and lay down by 3,000? The 3.6 doesn't even wake up till 4000?

 

[Gvsukids]

That's sure different than the diesels I used to own - 2700 was a top RPM. (but they were unstoppable)

Same, but that's close to the 3000 limiter.

 

[ShadowsPapa]

Same, but that's close to the 3000 limiter.

For reference, the earlier tractor I had before moving to Case, was IT - I had a 1086 and used others.
From the 1086 manual -
1086 high idle, 2640 , rated speed 2400.
The 1586 was higher at 2750 and 2500.
I went through 5 gallons of oil for each change with the 1086.
My later Case tractors I believe one of them was rated at 2100 RPM

 

[CrazyCooter]

For reference, the earlier tractor I had before moving to Case, was IT - I had a 1086 and used others.
From the 1086 manual -
1086 high idle, 2640 , rated speed 2400.
The 1586 was higher at 2750 and 2500.
I went through 5 gallons of oil for each change with the 1086.
My later Case tractors I believe one of them was rated at 2100 RPM

Most of the modern Class 8 tractor stuff is making peak tq well below 1000 rpm! You can almost count the exhaust pulses as you pass them climbing a hill. Pretty crazy technology!

 

[ShadowsPapa]

Most of the modern Class 8 tractor stuff is making peak tq well below 1000 rpm! You can almost count the exhaust pulses as you pass them climbing a hill. Pretty crazy technology!

I had a neighbor who had one of the fairly large JD 4x4 tractors - it was a big tractor but they had a fair sized operation.
I had what was at that time, the biggest 2 wheel drive tractor Case made.
Tom bragged about the power of his big new JD tractor (mine was used - wish I could recall the model now, bet I have pics of it.
He got to bragging about the low-end grunt of his JD and how it pulled his big chisel like nothing. I told him my Case could pull it no problem. He laughed and challenged me - he'd pull his chisel out to the middle of one of his fields that was right across the road from my fields. (the soil there was heavy) and he'd leave the chisel in the ground and unhook from it. If I could hook up and pull it the rest of the way across (about 1/4 mile) without raising the plow, he'd buy me a steak dinner at my choice of places.
I hooked up (connected all hoses - just in case), biggest hitch pin I had, and readied everything - throttle to max, started the pull, nice black smoke out the stack, and proceeded to pull that chisel plow, deep in the ground, from a dead stop. Part way across I shifted up a gear and finished the pull to the other corner of the field. I jokingly asked if I should leave it connected and I'd finish plowing for him. He shut up about my Case tractors.

Yeah, you think back to how capable things were back then, in a 1980s tractor and it's no real surprise how much they can get out of lesser displacement and lower RPM today.

 

[dawghauler]

Max tow comes with4.10 the trans will automatically select the right gear for the load being towed. Towing in 8th will net crappy mpg being in 7th mpg will be a little better but still crappy. These things get crappy mpg towing and run in the low to mid 3000 rpm range.

 

[Michael@WeGo4WhlLow]

Jaun, here is my setup! It's about 6600 LBS and we tow all over the country with no problems at all.
1) Gears 4:56. It will run you about $1600 to $2000. World of difference, no trying to find a gear all the time. Goes to 7th or 8th and holds there. I do run 35", but they are on the small side.
2) Air bags, I run the firestone with 38-40 PSI. They are going for around $130. E-trailers is a great go to and has good video. Also, there are number great threads here.
3) Redarc brake controller. Cost around $220-$240. Its amazing, the Jeep stops perfect with the trailer on the back. Love it!
4) Making sure you trailer is balanced with the proper tongue weight. I have mine at 700 LBS. (10% of total) and there is no sway at all. Take your time to get this correct.
5) Making sure you trailer is level. Having the right drop hitch is key here. You want the jeep and the trailer nice and level.
Spending a little time setting up the Gladiator to tow is well worth it. We have 80K miles on ours and it only 2 years old. We head to Co, Wy, Ut, Ca, Az, Mo, Nv all the time and do about 30 classes a year.
Good luck...

 

[Stinggrey 21 Rubi]

Find some small take off wheels and tires and try towing with those. You can do the math and get the final drive ratio to equal what your current tire size is with 4.10:1. Also, bigger tires always put bigger stress on brakes regardless of gear changes

 

[KX L]

Not likely that I would re-gear my JT with 4:56 or 4:88 unless I happened to "win" a full set of aftermarket axles.

Why wouldn't you re-gear without new axels?

 

[dcmdon]

Just for kicks - anyone recall the days when highway cruising speeds meant your engine was running 3,000 RPM, maybe more? My 70 had 3.15 gears, 3,000 RPM at highway speeds. I wonder what those guys running 3.54 gears were hitting on the highway!?

My 2005 Miata turned 3700 rpm at 70 mph.

My Gladiator (4.10 gears with 315/70s) turns under 2000 rpm at 70 mph.

 

[Blade1668]

Why wouldn't you re-gear without new axels?

I was referring to changing ratio from as my JT "Max-Tow" has 4:10s and wouldn't want to spend a thousand bucks plus for changing from (4:10) to 4:56 or 4:88 not a substantial enough change. Then going to lower ratio (5:13s) would probably mean going to a really large tire size "40s" which would make the axles M210 and M220 tubes, center section, R&P the fuse to break, bend or fail. The M210 M220 axles are good axles but by the time you upgrade everything needed it would probably be more cost effective (long term) to just find (and build) or order a set of built axles to bolt right in to point of even 6 lug pattern rims too. AKA ton axles. "D60s,D70s, 14 bolt" size axles. Yeah we see the U-tubers and others "doing it" and "never having" a problems.

In past I re-geared my XJ from 3:54 high pinion D30 and D44 rear to 4:56 knowing that I would be running 33s or 35s tires. It actually kept the speedometer/odometer fairly accurate without needing to change the speedometer gear. It was for rock crawling on E. side of Mississippi River and trails. Now my 05 Wrangler Unlimited came with 3:73 gears low pinion D30 and D44 rear, if I was going to regear it would be 4:88 (but a change to a high pinion D30 or D44 if I would best too). It's a logical choice of mine that if your going to do a gear change it shouldn't a small change but needs to still be reasonably for the axles strength, tire size and use. I've currently got a set of heavy MT 33s on it.

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