I've read the manual rated only to 2k lbs because you'll chew up the clutch. I towed way more than that with it but yeah, the clutch got toasty at times. Either way, the range math makes this tough. I think packing batteries into the XJ you're only going to get just a bit north of 100mi range, before you stick 7000lb behind it.
Planning 1990 Jeep Cherokee conversion
So I have this Jeep XJ that i bought for 2k about 5 years ago from a family friend that was a metal worker(hence the custom back)
![Wheel Automotive parking light Car Tire Plant]()
i had a donor ICE engine that I was going to swap it to. but the shop that I had it at took the jeep motor out, sold it, closed the business, and the owner moved across the country.
So i have a shell thats been sitting around for years, and i figured this would be a cool build.
My plan hasnt gotten very far yet but some of the ideas ive had so far are:
II have some mechanical experience, zero metal fabrication experience, some electrical experience. But ive always been kind of a jack of all trades and i pick up on things quickly with good instruction
The range you are hoping to get (how many miles/charge)
looking for about 120 miles to start ( my daily average driving is just under 100 miles)
What level of performance you are hoping to get
Dont really need to go above 80mph, would like to be able to tow
How much money you are willing to put into your project
As much as required, as little as possible.
What parts you've already considered, if any.
nothing yet
Any ideas, suggestions, product recommendations, instructionals, or just general feedback welcome.
i had a donor ICE engine that I was going to swap it to. but the shop that I had it at took the jeep motor out, sold it, closed the business, and the owner moved across the country.
So i have a shell thats been sitting around for years, and i figured this would be a cool build.
My plan hasnt gotten very far yet but some of the ideas ive had so far are:
- Build a battery box where gas tank is, up through the bed for easy access.
- I would like a dual/tri motor with the "single gear transmissions" (i dont know the actual name)
- I plan on building a Solar camper that will have panels on the roof and a large battery system so i would like to have a port on the back to allow the jeep access to the campers batteries to extend towing range
II have some mechanical experience, zero metal fabrication experience, some electrical experience. But ive always been kind of a jack of all trades and i pick up on things quickly with good instruction
The range you are hoping to get (how many miles/charge)
looking for about 120 miles to start ( my daily average driving is just under 100 miles)
What level of performance you are hoping to get
Dont really need to go above 80mph, would like to be able to tow
How much money you are willing to put into your project
As much as required, as little as possible.
What parts you've already considered, if any.
nothing yet
Any ideas, suggestions, product recommendations, instructionals, or just general feedback welcome.
21 - 34 of 34 Posts
...and brakes, and frame reinforcement, and cooling and ballast.
There's a reason a Ford F-450 weighs over 8000 lb. Empty.
There's a reason a Ford F-450 weighs over 8000 lb. Empty.
Company's here in the UK (electric classic cars) manage to fit the 100kWh Tesla battery in a short wheel base Landrover defender - 60% in a box in the engine bay, the rest where the fuel tank was. I don't know how that space compares exactly to the XJ but I would say fairly similar as both have space for V8 engines swaps.I've read the manual rated only to 2k lbs because you'll chew up the clutch. I towed way more than that with it but yeah, the clutch got toasty at times. Either way, the range math makes this tough. I think packing batteries into the XJ you're only going to get just a bit north of 100mi range, before you stick 7000lb behind it.
They suggest a defender with the 90kWh battery has a range of 150miles. Surely an XJ is 'slightly' more aero dynamic than a defender! They are definitely a lot lighter.
They mount the large model S motor longitudinally and change the gear ratio to something more like 4:1 so it works with the axle ratios, rather than 9:1.
Manual transmissions in light-duty vehicles have lower towing ratings than automatics, because drivers tend to burn out clutches with heavy loads on light vehicles.In the UK the 4.0 Auto XJ is rated for 3250kg which is 7165Ib's
Manual's seems to be rated a lot lower at 2500kg = 5511lb's
Jeep Cherokee (1993 - 2001) 4.0 Classic 5d Auto
Obviously we use a different hitch type Euro vs US - but it would be with the same frame/chassis. Don't know if there are axle differences between the man/auto? but if there are it would be simply to fit up-rated axles.
European towing ratings are routinely much higher than North American ratings, and it has nothing to do with structure, axles, suspension, brakes, or the hitches (the Euro standard for recreational trailers is a 50 mm ball, that's slightly under 2" diameter). The difference is due to different conditions, including lower speed - in most European countries cars towing trailers are limited to 80 km/h (50 MPH) and wouldn't normally go very far per day, while here people expect to tow at 100 km/h or more all day. Euro trailers are also different, with the mass more concentrated in the middle for better stability so they can get away with less tongue weight, so handling the weight on the hitch is less of a concern.
There's no reason a manual transmission can't be designed with a better towing capacity rating, all manual (proper) Landrovers can tow upto 3500kg - 7700Ibs (which is the maximum allowed for the 50mm euro ball hitch) Can go higher upto 'I think' 4000kg (8800Ib) with coupled brakes and a different hitch but then you start getting into 'commercial' type driving licences.Manual transmissions in light-duty vehicles have lower towing ratings than automatics, because drivers tend to burn out clutches with heavy loads on light vehicles.
European towing ratings are routinely much higher than North American ratings, and it has nothing to do with structure, axles, suspension, brakes, or the hitches (the Euro standard for recreational trailers is a 50 mm ball, that's slightly under 2" diameter). The difference is due to different conditions, including lower speed - in most European countries cars towing trailers are limited to 80 km/h (50 MPH) and wouldn't normally go very far per day, while here people expect to tow at 100 km/h or more all day. Euro trailers are also different, with the mass more concentrated in the middle for better stability so they can get away with less tongue weight, so handling the weight on the hitch is less of a concern.
What would normally result from the lower towing weight limit implied to manuals is if they have reused a transmission/clutch from a lower powered/smaller vehicle - the Landrover Freelander series I for example re-used a car manual transmission and the clutch was no good for HD off roading or towing.
When vehicles are certified for towing in the UK, the trailers used are not caravans - they are usually smaller/lower and more dense - so less effected by cross winds, so while 'legally' you could tow a 3.5 tonne caravan (not even sure if there is a 3.5T caravan for sale in the UK - most max out arround 2T) its probably not recommended - due to cross wind stability. the caravan club have a ruel of thumb for caravan weights (not a legal limit) of upto 80% of the tow vehicle's GVM or upto 100% for experienced drivers - with obviously ideal weight distribution.
In addition to the certified max towing limit, vehicles are also rated for their maximum down load 'D'/tongue weight the hitch can take - along with their max train weight - Legally none of these can be exceeded.
Regarding speed limits - UK (my home country) speed limit when towing a caravan on a motorway is 60mph, with many big SUV's (Rangerovers etc) 'illegally' doing more like 65 - 70+mph.
In Europe the speed limit is varied and includes weather condition (bad weather - lower speed) but seems to be between 50 - 60mph with gross train weight above 3500kg (7700Ibs) and 50 - 80mph with a gross train weight less than 3500kg (7700Ibs)
A game changer on modern vehicles in Europe (do you have it in the US?) is TSP (trailer stability program) where vehicle sensors monitor for snaking/yaw while towing and use the ABS/Traction systems to counter act it & correct it.
Also we have friction hitches (do you have these in the US?) where the caravan hitch has friction pads which clamp a dry tow ball, again to reduce snaking.
Yes, electronic trailer stability programs are now common on North American vehicles which are intended for towing; that's not a factor in the difference between Euro and North American ratings. Of course an EV conversion is unlikely to keep any such system functional, and most vehicles being converted (including the Cherokee in this case) never had this capability.A game changer on modern vehicles in Europe (do you have it in the US?) is TSP (trailer stability program) where vehicle sensors monitor for snaking/yaw while towing and use the ABS/Traction systems to counter act it & correct it.
The friction-on-ball couplers commonly used in Europe are not used here at all. One reason is that tow balls here are generally stud-mounted, so clamping on the ball risks loosening it in turns. Instead, there are crude sliding bar devices, and various schemes integrated with weight-distributing (WD) hitch systems. WD hitches are generally not used on Europe, but are common here on recreational trailers over a couple of tons. WD is even required above a certain trailer weight for some vehicles, on the assumption that the corresponding hitch weight will be too high; North American trailers run a higher tongue weight (as a fraction of trailer weight) than in Europe.Also we have friction hitches (do you have these in the US?) where the caravan hitch has friction pads which clamp a dry tow ball, again to reduce snaking.
For the proposed size of trailer, especially with a vehicle as short in wheelbase as the Cherokee, the builder should probably assume that a WD hitch will be used.
By the way, the unstable motion that Europeans call "snaking" is what North Americans call "sway".
Again, the biggest problem is typically not the transmission itself, it's the clutch. Yes, a very low first gear ratio can be selected to make it easier on the clutch, and in a 13-speed heavy truck transmission that's fine, but in a light vehicle 5-speed that's an undesirable compromise. A high-capacity clutch could be used, but people don't want a heavy and long-travel clutch pedal. And then there's generally incompetent non-commercial driver which the vehicle manufacturer can't control (unlike the automatic transmission that they can), which may be the biggest factor.There's no reason a manual transmission can't be designed with a better towing capacity rating, all manual (proper) Landrovers can tow upto 3500kg - 7700Ibs (which is the maximum allowed for the 50mm euro ball hitch) Can go higher upto 'I think' 4000kg (8800Ib) with coupled brakes and a different hitch but then you start getting into 'commercial' type driving licences.
What would normally result from the lower towing weight limit implied to manuals is if they have reused a transmission/clutch from a lower powered/smaller vehicle - the Landrover Freelander series I for example re-used a car manual transmission and the clutch was no good for HD off roading or towing.
The net result is that in a vehicle like a Cherokee, the towing rating will be lower with the manual transmission, regardless of what could be done with a different vehicle under different circumstances. In full-size pickup trucks, when they were still available with manual transmissions, even the manuals had high towing capacity... but almost no one wants to drive those things. The Cherokee is sturdier than a Freelander, but still basically just a car; it's not a commercial vehicle. Some Cherokees have the same transmission as some pickup trucks, so for some of them this isn't the vehicle's towing limitation.
The details don't matter to an EV conversion anyway, except that if a manual transmission is used the lower towing rating rated to the clutch can be ignored - the electric powertrain will become its own limitation, and no one will determine that for the builder. The strongest manual found in a XJ Cherokee is probably the New Venture Gear 3500, but even though it was used in full-sized pickup trucks it would be marginal for the load considered in this conversion... regardless of the clutch.
Again, the biggest problem is typically not the transmission itself, it's the clutch. Yes, a very low first gear ratio can be selected to make it easier on the clutch, and in a 13-speed heavy truck transmission that's fine, but in a light vehicle 5-speed that's an undesirable compromise. A high-capacity clutch could be used, but people don't want a heavy and long-travel clutch pedal. And then there's generally incompetent non-commercial driver which the vehicle manufacturer can't control (unlike the automatic transmission that they can), which may be the biggest factor.
The net result is that in a vehicle like a Cherokee, the towing rating will be lower with the manual transmission, regardless of what could be done with a different vehicle under different circumstances. In full-size pickup trucks, when they were still available with manual transmissions, even the manuals had high towing capacity... but almost no one wants to drive those things. The Cherokee is sturdier than a Freelander, but still basically just a car; it's not a commercial vehicle. Some Cherokees have the same transmission as some pickup trucks, so for some of them this isn't the vehicle's towing limitation.
The details don't matter to an EV conversion anyway, except that if a manual transmission is used the lower towing rating rated to the clutch can be ignored - the electric powertrain will become its own limitation, and no one will determine that for the builder. The strongest manual found in a XJ Cherokee is probably the New Venture Gear 3500, but even though it was used in full-sized pickup trucks it would be marginal for the load considered in this conversion... regardless of the clutch.
Would using a transmission increase or decrease the towing capacity versus not using a transmission in an ev conversation?
The caravan (travel trailer) issue applies here, too. While towing rating were determined inconsistently - and often questionably - for many years, an SAE testing standard was developed a couple decades ago and is now is widespread use: SAE J2807. It defines a trailer size (including frontal area) for a given trailer weight, which corresponds to a cargo trailer that is significantly smaller than a typical travel trailer of that weight. The standard even gives specific suitable trailer models for example weights... and they're cargo trailers that are both narrower and lower than travel trailers of that weight.When vehicles are certified for towing in the UK, the trailers used are not caravans - they are usually smaller/lower and more dense - so less effected by cross winds, so while 'legally' you could tow a 3.5 tonne caravan (not even sure if there is a 3.5T caravan for sale in the UK - most max out arround 2T) its probably not recommended - due to cross wind stability.
Trailer weight ratings here are assigned by vehicle manufacturers, and have no legal force.
In addition to the trailer weight limit, many vehicles also have a trailer frontal area limit, which is widely ignored. The purpose of the limit is to reflect the sustained power demand, and therefore load on the powertrain, due to aerodynamic drag. Most travel trailers will exceed the frontal area limit for many vehicles which are used to tow them.
You will have a transmission. Most EVs have a fixed-ratio (or "single speed") transmission, because the electric motor works acceptably throughout the vehicle's speed range without changing the gear ratio ("shifting"). Many conversions use the vehicle's original transmission only because that is the easiest method for converting those vehicles, but a multi-ratio (e.g. five-speed) transmission does provide the option to use a lower gear at low speeds and higher gear at high speed, keeping the motor closer to the ideal speed and possibly heating up less under heavy load (which would help reliability when worked hard).Would using a transmission increase or decrease the towing capacity versus not using a transmission in an ev conversation?
Yeah sorry that's what I meant was the ICE transmission or the single speed.You will have a transmission. Most EVs have a fixed-ratio (or "single speed") transmission, because the electric motor works acceptably throughout the vehicle's speed range without changing the gear ratio ("shifting"). Many conversions use the vehicle's original transmission only because that is the easiest method for converting those vehicles, but a multi-ratio (e.g. five-speed) transmission does provide the option to use a lower gear at low speeds and higher gear at high speed, keeping the motor closer to the ideal speed and possibly heating up less under heavy load (which would help reliability when worked hard).
I don't have any of the native power train unfortunately. So I was going to go the single speed option if I could financially, My backup plan was to use a gm donor transmission (people LS swap everything so the availability of parts is nice)
You may need a multispeed to crawl up/down a steep (6%) grade with a heavy trailer.
FWIW, my F350 Ford smoked the clutch (to where I was forced to clutchless shift in Illinois to keep what little clutch was left for launch) going up Vale Pass on I-70 in Colorado while pulling a heavy trailer. 6 speed manual. The problem? Not dropping a gear or two vs going 55-65mph up the hill and having a torquey drive element (diesel). Makin' time, baby! 😂
FWIW, my F350 Ford smoked the clutch (to where I was forced to clutchless shift in Illinois to keep what little clutch was left for launch) going up Vale Pass on I-70 in Colorado while pulling a heavy trailer. 6 speed manual. The problem? Not dropping a gear or two vs going 55-65mph up the hill and having a torquey drive element (diesel). Makin' time, baby! 😂
When I worked at Landrover a couple of decades ago as an apprentice we had a project looking at the clutch weight of the Defender and if it was suitable for 20th percentile people! The outcome was probably not but going to a powered clutch was not economically viable.Again, the biggest problem is typically not the transmission itself, it's the clutch. Yes, a very low first gear ratio can be selected to make it easier on the clutch, and in a 13-speed heavy truck transmission that's fine, but in a light vehicle 5-speed that's an undesirable compromise. A high-capacity clutch could be used, but people don't want a heavy and long-travel clutch pedal. And then there's generally incompetent non-commercial driver which the vehicle manufacturer can't control (unlike the automatic transmission that they can), which may be the biggest factor.
21 - 34 of 34 Posts
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