[JimHansen77]

Hello Everyone

I’m looking for feedback from folks who have gone from an OEM fuel tank to the MTS 0065 or vice versa.

I’ve been chasing a fuel supply and sensor problem that ultimately resulted in dropping the fuel tank on my 1993 4L YJ automatic. I learned that a previous owner had installed the aftermarket MTS 0065 tank and the aftermarket MTS YJSP-20 skid plate (photos below - I also included a photo of what I believe is an OEM tank). I also learned that the dimensions of the tank appear to cause some issues.

There were many interesting discoveries:

• The first thing I noticed was that the filler and vent necks had very little clearance below the frame and a body panel, resulting in the hoses being nearly abraded through. It also appears that the geometry of the filler and vent necks are different from OEM as there was some narrowing of the hoses due to the angle they had to be bent to connect to the tank.
• Next, I noticed that there was a location on the front right of the tank that was rubbing against a frame cross-member. Not enough to cause significant damage, but I can imagine it would have caused trouble eventually.
• Poking around online I learned that the MTS tank requires ¾” to 1” spacers between the frame and the skid plate.
• I noticed that the top of the tank had collapsed inward. I can only guess that it had something to do with thermal expansion…perhaps an over-tightening of the straps that secure the tank to the skid plate?
• The length of the sending unit wiring was so short that the tension required to plug it into the wiring loom resulted in increased stress at the sending unit fitting which broke the wire insulation at the fitting, allowed corrosion, and apparently created intermittent fuel pump and sensor problems.
• Dropping and re-installing the fuel tank is a real pain, requiring multiple blood sacrifices to the god of knuckles.

I’ve reinstalled the tank with a new sending unit (after extending the length of the wiring), new hoses, and ¾” spacers (using pieces of square steel tubing) between the frame cross members and the skid plate.

Here are my questions:

1. I’m uncomfortable with the need to use spacers to provide adequate space above the tank. That puts the mounting bolts in a bending mode if the skid plate is struck, which is likely to fail much sooner than the skid plate itself. Any views on this?

2. I’m uncomfortable with the collapsed top of the tank. Has anyone else encountered this problem?

3. To me, finding an OEM tank at a pick-and-pull or on eBay feels like a wise move. I know it’ll be 30 years old, but at least it will fit. Thoughts?

Thanks,

Jim

 

[agalloch07]

The only MTS tank i have a little experience with was a tank my friend put on his 1979 J10. It fit fine and was really thick and extremely well made and i planned on buying one for my YJ if it ever needed replaced. But i have no experience with their YJ tank so your post is concerning.

I have no idea why the top would cave in. Maybe MTS designed it to work with a body lift? I have no idea.

 

[Got it at last]

This is just my opinion, but I have nothing against MTS products, I use their senders in my Jeeps. But if I can find an OEM part I'll take it anyday over anything made this day and age. JMHO.

As far as the collapsed tank I'd be inclined to examine the exhaust routing closely to see if that is the root cause.

 

[JimHansen77]

This is just my opinion, but I have nothing against MTS products, I use their senders in my Jeeps. But if I can find an OEM part I'll take it anyday over anything made this day and age. JMHO.

As far as the collapsed tank I'd be inclined to examine the exhaust routing closely to see if that is the root cause.

You're thinking the exhaust runs too close, heats up the tank, the tank tries to expand but the straps won't let it and so it collapses? That's a solid hypothesis, GitL. I can say for certain that the exhaust routing is stock. I can also say that one of the stated features of the MTS skid plate is a heat shield between the tank and the exhaust. That heat shield is painted black, however. Maybe I can stick some reflective paint on there, or something.

 

[Got it at last]

May not be that, possibly gas cap not venting. There was a post a couple years ago of a similar issue. Can't find it or remember what was the remedy.

 

[dgsimick]

Hello Everyone

I’m looking for feedback from folks who have gone from an OEM fuel tank to the MTS 0065 or vice versa.

I’ve been chasing a fuel supply and sensor problem that ultimately resulted in dropping the fuel tank on my 1993 4L YJ automatic. I learned that a previous owner had installed the aftermarket MTS 0065 tank and the aftermarket MTS YJSP-20 skid plate (photos below - I also included a photo of what I believe is an OEM tank). I also learned that the dimensions of the tank appear to cause some issues.

There were many interesting discoveries:

• The first thing I noticed was that the filler and vent necks had very little clearance below the frame and a body panel, resulting in the hoses being nearly abraded through. It also appears that the geometry of the filler and vent necks are different from OEM as there was some narrowing of the hoses due to the angle they had to be bent to connect to the tank.
• Next, I noticed that there was a location on the front right of the tank that was rubbing against a frame cross-member. Not enough to cause significant damage, but I can imagine it would have caused trouble eventually.
• Poking around online I learned that the MTS tank requires ¾” to 1” spacers between the frame and the skid plate.
• I noticed that the top of the tank had collapsed inward. I can only guess that it had something to do with thermal expansion…perhaps an over-tightening of the straps that secure the tank to the skid plate?
• The length of the sending unit wiring was so short that the tension required to plug it into the wiring loom resulted in increased stress at the sending unit fitting which broke the wire insulation at the fitting, allowed corrosion, and apparently created intermittent fuel pump and sensor problems.
• Dropping and re-installing the fuel tank is a real pain, requiring multiple blood sacrifices to the god of knuckles.

I’ve reinstalled the tank with a new sending unit (after extending the length of the wiring), new hoses, and ¾” spacers (using pieces of square steel tubing) between the frame cross members and the skid plate.

Here are my questions:

1. I’m uncomfortable with the need to use spacers to provide adequate space above the tank. That puts the mounting bolts in a bending mode if the skid plate is struck, which is likely to fail much sooner than the skid plate itself. Any views on this?

2. I’m uncomfortable with the collapsed top of the tank. Has anyone else encountered this problem?

3. To me, finding an OEM tank at a pick-and-pull or on eBay feels like a wise move. I know it’ll be 30 years old, but at least it will fit. Thoughts?

Thanks,

Jim
View attachment 4531943 View attachment 4531944 View attachment 4531945

Keep the fuel tank you have, you know it works, and holds fuel, a junk yard one may leak. As for spacing, add the spacers, bolts will bend way before they break. The collapsed top is probably due to someone not putting spacers in when they installed it and just saying, "tighten it down, it'll fit", I wouldn't worry about it, tanks not leaking, good to go. As an added thought, you still get to used the skip plate if you keep the tank.

 

[Luckymac]

Without actually seeing the tank and mounts, this is only a guess. You state the top of the tank collapsed inward. It's my guess that the top wouldn't have collapsed if the PO had used the spacers. I'm thinking without the spacers the PO tightened the tank into the rear floor that's what collapsed the top of the tank. It sounds like your PO was a hacker that thought he knew so much that he could ignore reading the instructions. And I also guess that the rub against the crossmember wouldn't have been noticeable had the spacers been installed at the time of the original tank installation.
If you are dead set against using the spacers, you can install a 1" body lift and get rid of the spacers.
Aftermarket stock style tanks are available, but you'll need the corresponding skid plate for a stock tank.
I bought an aftermarket skid plate that came with the muffler shield, but had to cut the shield off because the poly tank wouldn't fit with the shield in place. The stock skid plates don't have a muffler shield. Pics show the fit of the stock tank on the aftermarket skid plate, (pic #1) before cutting the muffler shield off and after (pic #2) cutting the shield off.

I like having a 1" body lift, so that's what I'd do. I removed a 2" BL in favor of the current 1" BL.

Good Luck, L.M.

 

[JimHansen77]

Without actually seeing the tank and mounts, this is only a guess. You state the top of the tank collapsed inward. It's my guess that the top wouldn't have collapsed if the PO had used the spacers. I'm thinking without the spacers the PO tightened the tank into the rear floor that's what collapsed the top of the tank. It sounds like your PO was a hacker that thought he knew so much that he could ignore reading the instructions. And I also guess that the rub against the crossmember wouldn't have been noticeable had the spacers been installed at the time of the original tank installation.
If you are dead set against using the spacers, you can install a 1" body lift and get rid of the spacers.
Aftermarket stock style tanks are available, but you'll need the corresponding skid plate for a stock tank.
I bought an aftermarket skid plate that came with the muffler shield, but had to cut the shield off because the poly tank wouldn't fit with the shield in place. The stock skid plates don't have a muffler shield. Pics show the fit of the stock tank on the aftermarket skid plate, (pic #1) before cutting the muffler shield off and after (pic #2) cutting the shield off.

I like having a 1" body lift, so that's what I'd do. I removed a 2" BL in favor of the current 1" BL.

Good Luck, L.M.

Thanks, L.M. - I have to admit I didn't think of adding space by moving the body up. What is the level of pain and suffering associated with the body lift?

 

[Got it at last]

Not much pain at all unless you have rusted/frozen body puck bolts, (11) total plus the two front corners. Inspect stock rubber spacers for brittleness or disintegration and have replacements handy if needed.

Here's an 1.25" kit I have laying around. BL kits are all about the same, puck composition may vary.
This JKS kit has very hard urethane pucks.
Preload with PB blaster and loosen all bolts first. Lift one side and add pucks, then the other. Tighten completely once all are in place.
Radiator may need to be raised an inch to clear fan shroud.
Shift boots may need to be moved back and transmission tunnel may need to be trimmed a half inch if you gave manual trans. To allow for shifter throw or getting into reverse can be an issue. Since you have an automatic that's not going to be an issue.

 

[JimHansen77]

Not much pain at all unless you have rusted/frozen body puck bolts, (11) total plus the two front corners. Inspect stock rubber spacers for brittleness or disintegration and have replacements handy if needed.
View attachment 4531984
Here's an 1.25" kit I have laying around. BL kits are all about the same, puck composition may vary.
This JKS kit has very hard urethane pucks.
Preload with PB blaster and loosen all bolts first. Lift one side and add pucks, then the other. Tighten completely once all are in place.
Radiator may need to be raised an inch to clear fan shroud.
Shift boots may need to be moved back and transmission tunnel may need to be trimmed a half inch if you gave manual trans. To allow for shifter throw or getting into reverse can be an issue. Since you have an automatic that's not going to be an issue.

Thanks for the comprehensive reply. Does one also need to mess with the exhaust hangers?

 

[Got it at last]

Thanks for the comprehensive reply. Does one also need to mess with the exhaust hangers?

Only if you've exhaust work done and the shop mounted a new hanger to the tub, stock hangers are mounted to frame at rear and trans mount mid section.

 

[Luckymac]

Got it at last pretty much said it all, except you'll probably have to drop the radiator the distance you raise the body. As long as your steering shaft telescopes, it will self adjust to the new height.
I had a 2" BL and decided to drop down to a 1" BL. With the 2" BL, I had to hold the shifter in reverse or it would pop out of gear because the shifter hit the rear of the opening, even though I cut a good deal of the floor away to clear the shifter. My inner boot was torn and got in the way of the shifter even more, so I left it off with no ill effect.
Once I had the 1" lift in place, I had no problems with the shifter. I used all the original holes to hold the boot in place.

The biggest problem you'll encounter is frozen body bolts Your YJ is ~29 years old and depending on where it lived during it's long life, it could have no rust at all (desert areas) or could be held together with the factory undercoat (rust belt).
What I would suggest is drill a 1/8" hole in each body mount area where the caged nut plate resides. Then, on a daily basis, insert the straw from your favorite penetrating oil and give the caged nut plate a good shot of penetrating oil. I'd do that for at least a week. Some caged nut plates are easier to hit with penetrating oil from the top and others are accessed from underneath the vehicle. To do the topside oiling holes, you should be able to see where the nut plate boxes are by looking at where the body bolts are from underneath and then going topside and finding the middle area of where the spot welds are. For the ones that you have to do from underneath, I'd drill the small hole in the side of the mount. When you're all done, you can fill each hole with a dab of caulk and hit it with a shot of spray undercoat.

I strongly suggest using a ratchet and socket rather than an impact wrench to remove the bolts. Once you have the bolts broke free, by using a ratchet and socket, you can feel when the bolt binds because of rust. If the bolt feels like it's "stuck", tighten it up a couple turns and then give the bolt another shot of penetrating oil. Loosen again until it sticks, tighten, oil and loosen. Do this as many times as necessary until the bolt comes out. If you use an impact wrench, you can either break the bolt or twist the nut plate loose from the retaining cage. Even following my own advice, I broke one bolt at the rear, and my old heap is pretty much rust free. Being careful during the bolt removal process can save you a whole lot of work to cut the body open, free the nut plate, remove the broken bolt, weld the cut shut, prime, paint and undercoat.
Use Anti-Seize when reassembling the body bolts.

On my '87, the muffler is suspended from the body. My kit came with a couple longer brackets to allow the muffler to stay in place. That gave me a little more space between the floor and the muffler and I don't have any "hot floor" problems. On my '87, the cat is held in place with a bracket off the trans mount and the tailpipe tip is held in place by a bracket off the rear of the frame. In answer to your question, the exhaust system stays in place. The only thing that changes is a couple slightly longer brackets to hold the muffler to the floor. I don't know if Jeep used the brackets on the '93 models. Doing a body lift is really a simple job. The only complication is rusted body bolts.

Even with a small 1" BL, it's easier to get under the vehicle at the coin operated car wash to clean the oil, mud & crud from the bottom of the Jeep. Let us know how it goes.

Good Luck, L.M.

 

[Got it at last]

Got it at last pretty much said it all, except you'll probably have to drop the radiator the distance you raise the body. As long as your steering shaft telescopes, it will self adjust to the new height.
I had a 2" BL and decided to drop down to a 1" BL. With the 2" BL, I had to hold the shifter in reverse or it would pop out of gear because the shifter hit the rear of the opening, even though I cut a good deal of the floor away to clear the shifter. My inner boot was torn and got in the way of the shifter even more, so I left it off with no ill effect.
Once I had the 1" lift in place, I had no problems with the shifter. I used all the original holes to hold the boot in place.

The biggest problem you'll encounter is frozen body bolts Your YJ is ~29 years old and depending on where it lived during it's long life, it could have no rust at all (desert areas) or could be held together with the factory undercoat (rust belt).
What I would suggest is drill a 1/8" hole in each body mount area where the caged nut plate resides. Then, on a daily basis, insert the straw from your favorite penetrating oil and give the caged nut plate a good shot of penetrating oil. I'd do that for at least a week. Some caged nut plates are easier to hit with penetrating oil from the top and others are accessed from underneath the vehicle. To do the topside oiling holes, you should be able to see where the nut plate boxes are by looking at where the body bolts are from underneath and then going topside and finding the middle area of where the spot welds are. For the ones that you have to do from underneath, I'd drill the small hole in the side of the mount. When you're all done, you can fill each hole with a dab of caulk and hit it with a shot of spray undercoat.

I strongly suggest using a ratchet and socket rather than an impact wrench to remove the bolts. Once you have the bolts broke free, by using a ratchet and socket, you can feel when the bolt binds because of rust. If the bolt feels like it's "stuck", tighten it up a couple turns and then give the bolt another shot of penetrating oil. Loosen again until it sticks, tighten, oil and loosen. Do this as many times as necessary until the bolt comes out. If you use an impact wrench, you can either break the bolt or twist the nut plate loose from the retaining cage. Even following my own advice, I broke one bolt at the rear, and my old heap is pretty much rust free. Being careful during the bolt removal process can save you a whole lot of work to cut the body open, free the nut plate, remove the broken bolt, weld the cut shut, prime, paint and undercoat.
Use Anti-Seize when reassembling the body bolts.

On my '87, the muffler is suspended from the body. My kit came with a couple longer brackets to allow the muffler to stay in place. That gave me a little more space between the floor and the muffler and I don't have any "hot floor" problems. On my '87, the cat is held in place with a bracket off the trans mount and the tailpipe tip is held in place by a bracket off the rear of the frame. In answer to your question, the exhaust system stays in place. The only thing that changes is a couple slightly longer brackets to hold the muffler to the floor. I don't know if Jeep used the brackets on the '93 models. Doing a body lift is really a simple job. The only complication is rusted body bolts.

Even with a small 1" BL, it's easier to get under the vehicle at the coin operated car wash to clean the oil, mud & crud from the bottom of the Jeep. Let us know how it goes.

Good Luck, L.M.

Thanks, L.M. for your correction, "except you'll probably have to drop the radiator the distance you raise the body." Doing it in my head I went the wrong direction.

 

[Luckymac]

Doing it in my head I went the wrong direction.

Easy to do without the Jeep right in front of you. I know an 8.8 is an inch narrower than the stock D35, but I couldn't figure out why the front tires sat wider than the rear. And, I was looking right at my Jeep.

Good Luck, L.M.

 

[Jarhead Al]

Lots of good info above.

Here is a good write up on how to do a body lift.

Body Mount Bolt Locations (For BL) - Detailed Write-Up...

OK....I've seen many threads started about body lifts, body mount locations, the number of body mount bolts, how to remove them, etc., so I thought I'd start a detailed thread after I located all of mine. This thread was inspired by a post in an earlier thread about stuck and rusted body mount...

www.jeepforum.com

I recently did a 1" lift. I used a 3/8" drive rachet to start. Just so I didn't break any of the captive nuts. I can not over stress the importance of liberally applying your favorite penetrating oil daily for several days prior to even putting a wrench or socket on the body bolts. If you break off a captive nut, you will be using a 2-3" hole saw to cut your tub to get to them. PB Blaster and patience will be your friends here. It wasn't hard, just pay attention.

Good luck and Happy Jeeping