Towing capacity of my v8 XJ?

[TRCM]

This makes more sense to me than the 20 responses insisting that I'm going to tow a 20,000lbs trailer regardless of what anyone says . Thanks. Makes me insane when you ask a question and 10 guys show up to insist that what you're "going to do regardless of input" won't work. If I listened to that every time, I wouldn't have a 350hp lifted XJ getting 25mpg (with roof basket and carrier removed).

.........any discussion about doing something a stock Jeep wasn't designed to do is always met with confusion and anger........

. As of this year, >5000lbs are exempt, and >5000lbs air care is required, and there's no way I'll pass unless I absolutely destroy my engine, so I'm stuck with the sticker on the door, so I guess I'll just see what I can do with 5000.

Talk about butt-hurt....
1) Well, the trailblazer comparison doesn't make any more or any less sense. But you will never see it that way because it is not what you wanted to hear. You claim it makes more sense cuz it is similar to your jeep. True, but our comparison of a regular truck to your jeep is also just as true & makes just as much sense because we were not comparing for similarities, but for differences
2) Sounds like the law up there says the same thing as the law down here...ya can't do it
3) the 'discussion about doing something a jeep wasn't designed to do' had no confusion or anger in it that I saw, we were answering your question simply, because it is not 'designed' to do it, nor is it safe to do

And as to doing what you want.......Your replies below indicated your intentions (altho they seem to have changed now that you know the law).

With the V8, I can't imagine 10k being too much, except perhaps on very long steep climbs

That said, I'm just using 10,000 as a baseline as I know my motor can deal with it

Also again, I'm not trying to pull 12,000lbs. I said that is the number that comes with my driveline so I know I can easily drag that much behind me.

None of us ever said you were gonna tow 20,000 lbs....you did:

I have an 05 LM7 5.3L with an 05 4l65e transmission. This combination is used in the base model rated at 9000lbs (for the 2005 year), upgradeable to 11,500 with tow package.

I don't care what you say I'm going to pull 20,000". I'm asking for real world issues I'd have to address to safely increase my towing capacity, and figure out how far I can push it (safely). Once I have a number, I'll either build a trailer to match, or if the number is too low, I'll worry about the tow rig some other day and build whatever trailer I want.

All quotes from YOUR posts.

 

[blistovmhz]

Talk about butt-hurt....
1) Well, the trailblazer comparison doesn't make any more or any less sense. But you will never see it that way because it is not what you wanted to hear. You claim it makes more sense cuz it is similar to your jeep. True, but our comparison of a regular truck to your jeep is also just as true & makes just as much sense because we were not comparing for similarities, but for differences
2) Sounds like the law up there says the same thing as the law down here...ya can't do it
3) the 'discussion about doing something a jeep wasn't designed to do' had no confusion or anger in it that I saw, we were answering your question simply, because it is not 'designed' to do it, nor is it safe to do

And as to doing what you want.......Your replies below indicated your intentions (altho they seem to have changed now that you know the law).

None of us ever said you were gonna tow 20,000 lbs....you did:



And as to your intentions......







All quotes from YOUR posts.

I suspect you may have difficulty retaining concepts within' a sentence longer than 6 words, which renders any response futile. It would take more than 6 words per sentence to re-iterate and fully enunciate what I've actually written.

 

[TRCM]

Sticks & Stones.....

I have no difficulty understanding what you said...but what you meant, well, thankfully I can't read your mind.

It also appears I am not the only one who 'understood' your posts & comments the same way.

If you were to consider all the people in this discussion/post, you (1 person) would be the minority, and the rest (rest meaning more than 1) would be the majority. It certainly seems from the responses, that the majority (us) understood what you said/meant differently than the minority (you), so based on the law of averages, the indication is that the one who truly doesn't seem understand the diction used is actually the one who used it.

Again, quotes from your own posts.......................



BTW...what's with the apostrophe after the word within ??????

 

[blistovmhz]

Being in the majority doesn't make anyone right. Historically, the relationship is actually inverse. How many people were convinced the Earth was flat while a small handful of raving lunatics insisted all the data proved otherwise (they were usually burned at a stake or pressed to death).


"The donor vehicle (for engine) was rated to 11,600lbs." - This is fact. The context in which this was used was the maximum mass my engine could pull. My engine is actually beefier than the stock LM7 at this point and I'm making more HP and my cooling is adequate for 500HP for about 10 minutes (Had Griffin do the math for me, had another shop confirm).

"Get in an accident towing 8000 lbs behind a cherokee, and your insurance company will drop you & not pay, and the law will stick it up your kiester for being overweight." - You. This is not true here, as I keep stating. You increase your GVWR simply by telling your insurance provider to do so. If it's documented and they agreed (our insurance provider is the government, so they're both the provider and the authority), they can't **** you for towing precisely what they cleared you for.

"I have an 05 LM7 5.3L with an 05 4l65e transmission. This combination is used in the base model rated at 9000lbs (for the 2005 year), upgradeable to 11,500 with tow package. No, I'm not going to just pull whatever I can pull, regardless of input, which is why I'm bringing it up." - Me. Once again, re-iterating that I'm not planning on pulling any number at all, just that I'm trying to find the maximum safe number that my rig is capable of, or can be made capable of.

"Also again, I'm not trying to pull 12,000lbs. I said that is the number that comes with my
driveline so I know I can easily drag that much behind me. It's a baseline to work from, and I'm not asking "can I pull 12,000lbs, ps. I don't care what you say I'm going to pull 20,000". I'm asking for real world issues I'd have to address to safely increase my towing capacity, and figure out how far I can push it (safely). Once I have a number, I'll either build a trailer to match, or if the number is too low, I'll worry about the tow rig some other day and build whatever trailer I want." - Me, reiterating again, the exact same thing.

Find me somewhere where I said "I'm going to pull 12,000lbs" or "I want to pull 12,000lbs", or even "Maybe I can safely pull 12,000lbs". I have not. I have used that number as a baseline for what my motor can deal with, because the donor vehicle was rated to that number so I know a stock LM7 of that year with my transmission, can deal with that much mass. It would be silly to start with no baseline whatsoever, and it would be silly to start with a stock XJ as a baseline as what I'm driving is no longer anywhere near a stock XJ. A stock XJ doesn't make 300+ HP, isn't 5000lbs, has a shorter wheel base, weak brakes, flimsy unibody, suspension, and mounts, and the cooling wasn't up to the task. Mine does make >300HP and has the cooling to deal with more, is >5000lbs, has a longer wheel base, very beefy brakes, fully plated uni-frame. The rear suspension is the same as you'd find in the engines donor vehicle, and the front suspension is built to deal with the extra 2000lbs. Aside from the "shorter than a pickup" wheel base, my XJ is much closer to a full size truck than it is an SUV. What I've been trying to find with this thread, is what matters and what does not. If the stock XJ can pull 5000, mine can definitely pull more. The question was how much, and what would I need to increase that number.

Not once have I made a claim as to what I should be able to tow, nor what I planned to tow. A few people made a few good points in response to my actual questions, while several others flew off the handle about how I was saying I was going to go out and tow 12,000lbs.
Either way, issue is dead. Emissions testing rules out increasing GVWR for the next few years, and I'll try to design under 5000lbs, or I'll build an RV, or I'll borrow a truck.

 

[TRCM]

OK...clearly you know everything.

I was not talking about who was right or wrong with the majority/minority thing, but that what everyone else thought you said was different from what YOU thought you said. Maybe reading comprehension is your problem not ours ??

I also said up north, I'm not sure how it is, but down here........

I never said you were gonna tow 12k, or 10k....but I did say it is not legal to do here in a jeep.

And as for the insurance thing....well, you can tell your insurance here that you can tow more, and they will likely charge you more money. But once you have an accident and they investigate & check the vin and see you are NOT legally able to do what you claim, they WILL refuse to pay, and you WILL get a huge fine (1000s of dollars) for being overweight. I know someone personally that it happened to, and he was only overweight by 1500 lbs, and HE was fined AND had to park his rig and get someone else in a bigger truck to come drive it home for him.

And not sure how things work up there (there it is again), but when I registered the 3500 I mentioned, I had to go thru a lot of hassle to register it CORRECTLY, cuz the previous owner had lied about it's weight & capacity to get cheaper license plates & registration. No, they didn't check they just let him do it, but had I got stopped registered that way while towing, I was told by the officer at the weigh station, that I would have been fined in excess of $2500 and could have lost my license for 30 days.

That is how I know what the law is down here...so you go on driving up there, and maybe you'll be ok, but come down here like that, and you likely won't.

And lastly, while it seems to slip right over your head....What matters is what the VIN says....not what you do to it.....just like EVERYONE has told you.

 

[GordoSmasho]

This is why i stopped trying. It just becomes a pissing match. Dont need that drama.

On a side note. The only reason people tend to be more harsh with responses about questionable things is because people come to this forum for info and knowledge. We want to make it clear this forum doesnt support breaking the law or driving recklessly. Things you are describing have the possibility of ecouraging both.

 

[yossarian19]

The drivetrain, in the donor vehicle, was rated at 11,600lbs. Yea, the stock XJ was only rated for 5000 for very good reason, but most of those reasons are no longer valid on my rig.

The donor vehicle had a lot less tire (though less gear, too) and a lot more brake. Also, don't I recall you having cooling issues? Don't underestimate the stress towing will put on your cooling system. Factory tow packages usually include up-rated transmission cooling and frequently an up rated radiator, too.

You might get things moving with the 5.3 but if you can't get it stopped (and stopped in a straight line) you are fooling yourself about what you can "safely" tow.

How big are your front rotors? Rears?

 

[blistovmhz]

The donor vehicle had a lot less tire (though less gear, too) and a lot more brake. Also, don't I recall you having cooling issues? Don't underestimate the stress towing will put on your cooling system. Factory tow packages usually include up-rated transmission cooling and frequently an up rated radiator, too.

You might get things moving with the 5.3 but if you can't get it stopped (and stopped in a straight line) you are fooling yourself about what you can "safely" tow.

How big are your front rotors? Rears?

Yea, I was definitely having cooling issues, but after chasing the cooling system for a few weeks, I realised it was because of my scoop. The first temporary scoop (just there to make it legal to drive) was causing the under-hood air pressure to increase far enough that at highway speeds, I wasn't getting any flow through the rad. Built the new scoop which had closed top and sides, but while this helped a bit with the pressure, it didn't allow enough underhood heat out while wheeling. Those 8 header pipes makes a big difference in underhood temps. Was getting hot enough that my bit of trans fluid that had accumulated in the mud on the cross member started smoking. Buttoned up the trans and cleaned everything up and added some perforated sheet to the top of the scoop to let air out at low speed and the cooling issues seem to be solved. Trans still doesn't quite keep up to the motor cooling under severe load, but still haven't pushed it over 99C.
Currently, doing 140km/h up an 8% grade for 5 minutes (from the bottom, to the top of the mountain), motor peaks around 101C and trans peaks around 99C. I don't like the trans being that hot (I know it's perfectly fine, but I like some buffer), so I'll be doing some more work to the trans cooler and giving it it's own fan.
Either way, that 140 run was with 4 people, 800lbs of extra gear, in 40C (that's 104F) weather and barely broke 100C, and I've got a few idea's to increase the cooling further so I doubt it'll be a problem. Also, the rad I've got currently is rated to 500hp. The overall cooling surface is about 40% larger than the stock S1500 (non-tow) which i believe is right around the same size as the tow package version. My trans cooler would need work for sure, but that's a minor detail.

Don't know my rotor sizes off hand. Currently running the WJ fronts and KJ rears. I think they're both around 305mm? Jeep stops sick fast. On that same trip doing the 140 up the mountain, I also did a few braking tests, so the same load. Coming back down the mountain I rode the brakes the whole way (wanted to see if they'd start fading/smoking) and at the bottom I hammered on them. Stopped scary quick. Granted that's only around 6300lbs total, but I would never pull a trailer over 1000lbs without trailer brakes. If I was going to be towing anything on a regular basis, I'd be going tonnes anyway. Has always been the plan. Just holding off until I really need them because I really don't like the big pumpkins.

 

[DieselSJ]

Sticks & Stones.....

I have no difficulty understanding what you said...but what you meant, well, thankfully I can't read your mind.

It also appears I am not the only one who 'understood' your posts & comments the same way.

If you were to consider all the people in this discussion/post, you (1 person) would be the minority, and the rest (rest meaning more than 1) would be the majority. It certainly seems from the responses, that the majority (us) understood what you said/meant differently than the minority (you), so based on the law of averages, the indication is that the one who truly doesn't seem understand the diction used is actually the one who used it.

Again, quotes from your own posts.......................



BTW...what's with the apostrophe after the word within ??????

So full of win.

 

[1-tonxj]

6-7,000lbs is all you will move with a 5.3 in a reasonable fashion ...lol...forget those inflated 10-12k numbers those numbers are based more on what the rig ran control in stopping and handling and will require trailer brakes to reach those towing numbers , but...lol...man figure 50-60% of that max to be a load that you would move with any authority . With trailer brakes and proper spring rates in rear of the XJ I can't see why you would not be able to tow just like a puckup...lol...my Ram is Cummins 6.7 the suspension is simply stamped steel control arms and likr 10g brackets for the links in front most likely your XJ suspension is heavier than most Diesel pickup from factory , so it just comes down to what the rig can control and stop , which should be the same as a pickup in the 1500 range ...and that means 6k is about the sweet spot for being able to move the load .

 

[Ronbo]

My LC9 5.3L Suburban is rated to tow 7900lbs. That's a 6klb vehicle with the 6L80E trans. Nearly 30" greater wheelbase, 10" wider, stronger chassis and suspension, waaaay bigger brakes, E-range tires...... your overloaded XJ and it's 1/4 ton chassis would probably still be at the 5k factory rating. Add in a crosswind or a mountain, and you'd need a diaper to keep your seat clean.