Something is wrong with my baby...

[ccool416]

Hey I am new, so hello everyone. I have an awewsome black 95 xlt (with all the options) 5.8. I have almost too many mods to list, but here are a few..ceramic wrapped headers, Msd distributor,coil,wires. K&N, Jet module, No cats, Flowmaster,33inch muddeers on M.T classics bead lock..fridge inside...t.vs etc etc..I love my truck and have done mostly everything to it myself..Recently I have developed a vibration in the rear end depending on how I hit the gas pedal..It is only under very light exceleration..I think it is my rear end, but I am stumped..Please help..I did have my rear end rebuilt at a reputable place awhile back probably around 20 thousand miles ago..

 

[Seabronc]

Check your U-joints for slop.

Good luck,

>-

 

[Broncobill78]

Check your U-joints for slop.
Good luck,

>-

Yup, U-joint is the first thing I'd look at if it's something that varies w/the throttle. You didn't mention a lift so I assume it's still stock suspension so it's all probably tight but if you've lifted it & ESPECIALLY if you used lift blocks ck the leaf spring U-bolts. Lift blocks require longer U-bolts and that makes for a lever-effect under acceleration that tends to loosen the U-bolt nuts. But @ 12yrs old I'd bet you've still got factory U's in there so got get yourself a nice Spicer & be done with it.

 

[ccool416]

Check your U-joints for slop.
Good luck,

>-

I got under it and tried to move it in any direction and it is very tight..It looks to be in good condition except dry. There are no grease fittings that I can see.

 

[ccool416]

Yup, U-joint is the first thing I'd look at if it's something that varies w/the throttle. You didn't mention a lift so I assume it's still stock suspension so it's all probably tight but if you've lifted it & ESPECIALLY if you used lift blocks ck the leaf spring U-bolts. Lift blocks require longer U-bolts and that makes for a lever-effect under acceleration that tends to loosen the U-bolt nuts. But @ 12yrs old I'd bet you've still got factory U's in there so got get yourself a nice Spicer & be done with it.

I only have a three inch body lift, but have for some time now..

 

[Seabronc]

I got under it and tried to move it in any direction and it is very tight..It looks to be in good condition except dry. There are no grease fittings that I can see.

There should be grease fittings, but one of them on the Cardon Joint is impossible to get at on mine. Check there pictures out, you can't always see the damage or feel it by hand in the early stages. If yours haven't been greased they may look like this. Changing them is a relatively easy job.

Good luck,

>-

 

[Broncobill78]

There should be grease fittings, but one of them on the Cardon Joint is impossible to get at on mine. Check there pictures out, you can't always see the damage or feel it by hand in the early stages. If yours haven't been greased they may look like this. Changing them is a relatively easy job.
Good luck,

>-

Don't know if the grease ****** thing is brand specific but when I have shafts made up I specify Spicers and every double cardan joint I've had has come with that little cup instead of the standard grease ******. I have to switch adapters on the greaser and use a spike to grease them but there aren't any clearance issues like you get with standard *******. If you don't see a grease ****** then look for a small circular cup, it could easily be covered with old grease or dirt ,it should be right on the body itself in one of the V's just like the regular ones.

Take-em out and check the caps, good chance you've destroyed a few of the needles and the remaining needles & the mixed in debris provides enough resistance to feel tight when you ck by hand but not nearly enuf resistance when you put actual horsepower to it. Also, has it been worked on ? You'll vibrate quite a bit if you re-install the thing out of phase.

Me personally, I'd start by isolating the rear shaft to make sure that's what it is. Take the thing out, engage the front axel and go for a ride. If your vibration disappears then bingo go home and figure out just what's wrong with the shaft if it still vibrates then reinstall the shaft and move on to the next suspect. If it's still vibrating without the shaft then I'd start looking towards a bad wheel bearing or (depending upon driving style) perhaps a bent axle shaft. If you take it off-road there's a good chance you've dinged or bent the shaft & it's out of balance. If the vibration disappears when the shaft is out & the U's look good then it's probably either out of balance somehow (bent or dinged) or there's a problem with the CV (double cardan) joint and either way you'll want a shaft shop to look it over. If all that looks good then I'd check the Xfer-case & differential pinions, I've spun shafts off before & damaged the pinion without realizing it and then gone & spun the brand new shaft right off it on the way home from the shop so it's worth looking at them as well as the pinion bearings.

Now if all THAT doesn't give you enough to do an a warn sunny Sunday then you're a better man then me, I'm going out to duct-tape the hole in my windshield & wait for the Pats to start spanking the Colts @ 4.

Oh, yeah, if everything looks good I would quite honestly bring it back to the shop that rebuilt the rear end. Just tell them what it's doing and ask them to take a quick look at it. I've *seen* differential gear bolts back out over time when not loctited and it starts as a subtle vibration and then turns into a loud metal crunching sound, never any shame in asking a professional shop to take a look especially when they've done substantial or expensive work to it in the past.

 

[ccool416]

There should be grease fittings, but one of them on the Cardon Joint is impossible to get at on mine. Check there pictures out, you can't always see the damage or feel it by hand in the early stages. If yours haven't been greased they may look like this. Changing them is a relatively easy job.
Good luck,

>-

Okay, I will check again, Thanks..

 

[Broncobill78]

Okay, I will check again, Thanks..

One more thing, just take a look to be sure it isn't something silly like a thrown balancing weight from one of the wheels.

 

[ccool416]

Don't know if the grease ****** thing is brand specific but when I have shafts made up I specify Spicers and every double cardan joint I've had has come with that little cup instead of the standard grease ******. I have to switch adapters on the greaser and use a spike to grease them but there aren't any clearance issues like you get with standard *******. If you don't see a grease ****** then look for a small circular cup, it could easily be covered with old grease or dirt ,it should be right on the body itself in one of the V's just like the regular ones.
Take-em out and check the caps, good chance you've destroyed a few of the needles and the remaining needles & the mixed in debris provides enough resistance to feel tight when you ck by hand but not nearly enuf resistance when you put actual horsepower to it. Also, has it been worked on ? You'll vibrate quite a bit if you re-install the thing out of phase.

Me personally, I'd start by isolating the rear shaft to make sure that's what it is. Take the thing out, engage the front axel and go for a ride. If your vibration disappears then bingo go home and figure out just what's wrong with the shaft if it still vibrates then reinstall the shaft and move on to the next suspect. If it's still vibrating without the shaft then I'd start looking towards a bad wheel bearing or (depending upon driving style) perhaps a bent axle shaft. If you take it off-road there's a good chance you've dinged or bent the shaft & it's out of balance. If the vibration disappears when the shaft is out & the U's look good then it's probably either out of balance somehow (bent or dinged) or there's a problem with the CV (double cardan) joint and either way you'll want a shaft shop to look it over. If all that looks good then I'd check the Xfer-case & differential pinions, I've spun shafts off before & damaged the pinion without realizing it and then gone & spun the brand new shaft right off it on the way home from the shop so it's worth looking at them as well as the pinion bearings.

Now if all THAT doesn't give you enough to do an a warn sunny Sunday then you're a better man then me, I'm going out to duct-tape the hole in my windshield & wait for the Pats to start spanking the Colts @ 4.

Oh, yeah, if everything looks good I would quite honestly bring it back to the shop that rebuilt the rear end. Just tell them what it's doing and ask them to take a quick look at it. I've *seen* differential gear bolts back out over time when not loctited and it starts as a subtle vibration and then turns into a loud metal crunching sound, never any shame in asking a professional shop to take a look especially when they've done substantial or expensive work to it in the past.

Okay I will check again for the grease fitting even though I have had my truck since 95 and Have never seen it. i do grease all the other fittings and have looked before,because I have seen them on other vehicles. I have read some things saying non greasible types.Is that possible? How much are new joints? No one has worked on my rear for quite some time. My Baby has been parked for awhile while I put new headers got the heads done timing chain new pan gasket new motor and tranny mounts water pump carpet fridge brakes rotors drums repacked the bearings in the front installed new Mile Marker manual hubs and replaced the plungers in the back for the drum brakes which use to leak a little..My engine runs extremely strong and tight now. I run fully synthetic oil with no leaks..My suspension is very tight no squeeks or anything..Since doing all that work I took it for a couple of 300 mile trips (1 way) It started to happen on the way back from one of those trips. Like I said it is intermmittent. I can almost make it happen and or keep it from happening by the way I drive..it is only under almost no load when I am cruising It can happen at around 30-40 and around 70mph Once it does start vibrating though, If I accelarate the vibration picks up with it unless I either release and rehit the gas or stomp on it enough to make the Tranny downshift then it's gone..It is very frustrating. I have invested much money in my truck and love it very much..This is the only little glitch left before I move to all the crazy stuff I am going to do to the body.. . so I will start with the U joints looking for and greasing the fittings if possible then removing and inspecting..After that I will get back to you and thanks soo much..It is very hard to get good info on broncos and dealers don't want to help anymore, they say my truck is too modified > I will upload pictures now...

 

[ccool416]

One more thing, just take a look to be sure it isn't something silly like a thrown balancing weight from one of the wheels.

I will check,but the way I can feather or stomp the gas pedal to make it stop or start makes me think it is not the wheels which are new and have those flat metal strip type weights..Hard to fall off..

 

[ccool416]

Okay I will check again for the grease fitting even though I have had my truck since 95 and Have never seen it. i do grease all the other fittings and have looked before,because I have seen them on other vehicles. I have read some things saying non greasible types.Is that possible? How much are new joints? No one has worked on my rear for quite some time. My Baby has been parked for awhile while I put new headers got the heads done timing chain new pan gasket new motor and tranny mounts water pump carpet fridge brakes rotors drums repacked the bearings in the front installed new Mile Marker manual hubs and replaced the plungers in the back for the drum brakes which use to leak a little..My engine runs extremely strong and tight now. I run fully synthetic oil with no leaks..My suspension is very tight no squeeks or anything..Since doing all that work I took it for a couple of 300 mile trips (1 way) It started to happen on the way back from one of those trips. Like I said it is intermmittent. I can almost make it happen and or keep it from happening by the way I drive..it is only under almost no load when I am cruising It can happen at around 30-40 and around 70mph Once it does start vibrating though, If I accelarate the vibration picks up with it unless I either release and rehit the gas or stomp on it enough to make the Tranny downshift then it's gone..It is very frustrating. I have invested much money in my truck and love it very much..This is the only little glitch left before I move to all the crazy stuff I am going to do to the body.. . so I will start with the U joints looking for and greasing the fittings if possible then removing and inspecting..After that I will get back to you and thanks soo much..It is very hard to get good info on broncos and dealers don't want to help anymore, they say my truck is too modified > Also if I engage front wheels and disconnect rear how fast can I drive in 4H??

 

[bidibronco]

If you pull the drive shaft then you may as well check for "slop" in the rear pinion...

 

[Broncobill78]

Okay I will check again for the grease fitting even though I have had my truck since 95 and Have never seen it. i do grease all the other fittings and have looked before,because I have seen them on other vehicles. I have read some things saying non greasible types.Is that possible? How much are new joints? No one has worked on my rear for quite some time. My Baby has been parked for awhile while I put new headers got the heads done timing chain new pan gasket new motor and tranny mounts water pump carpet fridge brakes rotors drums repacked the bearings in the front installed new Mile Marker manual hubs and replaced the plungers in the back for the drum brakes which use to leak a little..My engine runs extremely strong and tight now. I run fully synthetic oil with no leaks..My suspension is very tight no squeeks or anything..Since doing all that work I took it for a couple of 300 mile trips (1 way) It started to happen on the way back from one of those trips. Like I said it is intermmittent. I can almost make it happen and or keep it from happening by the way I drive..it is only under almost no load when I am cruising It can happen at around 30-40 and around 70mph Once it does start vibrating though, If I accelarate the vibration picks up with it unless I either release and rehit the gas or stomp on it enough to make the Tranny downshift then it's gone..It is very frustrating. I have invested much money in my truck and love it very much..This is the only little glitch left before I move to all the crazy stuff I am going to do to the body.. . so I will start with the U joints looking for and greasing the fittings if possible then removing and inspecting..After that I will get back to you and thanks soo much..It is very hard to get good info on broncos and dealers don't want to help anymore, they say my truck is too modified > I will upload pictures now...

Whoa, whoa, whoa there Hoss. Ok, *much* better info this time around. First let me start off with this, it's a 95 and you've had it since 95 ? Impressive and my hat is off to you, I think that's the kind of dedication & love we ALL like to see. Moving foward, you say the shaft has never been touched ? Seems to me there are indeed "Lubed for life" U-joints out there, not that I buy them but Factories love the things and no, they DO NOT have grease ******* so if you've looked and can't find anything then I strongly suspect that what you're looking at are ORIGINAL factory U-joints and probably your prime suspects.. Ditch them immediately, after 12 yrs you've gotten you money's worth out of them (really, you have) and replace them with a set of Spicer U-joints. If someone here has a better brand of U-joint to recommend then please speak up now, otherwise pls trust me on this one and go & SPECIFY that you want a set of *spicer* replacement U-joints, don't settle for Brand-X or another set of Lubed for life joints. Start there. If that doesn't fix it then again I refer to your post and while you've had the front wheel bearings replaced you didn't say jack about the rears, time to pony-up and replace those as well. Granted it's not as easy a job as doing the fronts but with the age and probable milage you have I would most certainly replace the rears, once again you've gotten your money's worth out of them. If U-joints and rear bearings don't make this go away (and really, I think they will) then it's time to start looking at pinion bearings or an out-of-balance shaft. Doesn't sound like you beat it so I'd put axle shafts low on the list, start with replacing the original U-joints with quality (greasable) spicers and then the rear wheel bearings. Those are the most likely candidates and also the cheapest fixes, if those don't fix it the problem is deeper & going to be more expensive but I promise that ignoring it will eventually be even MORE expensive than this.

 

[ccool416]

Whoa, whoa, whoa there Hoss. Ok, *much* better info this time around. First let me start off with this, it's a 95 and you've had it since 95 ? Impressive and my hat is off to you, I think that's the kind of dedication & love we ALL like to see. Moving foward, you say the shaft has never been touched ? Seems to me there are indeed "Lubed for life" U-joints out there, not that I buy them but Factories love the things and no, they DO NOT have grease ******* so if you've looked and can't find anything then I strongly suspect that what you're looking at are ORIGINAL factory U-joints and probably your prime suspects.. Ditch them immediately, after 12 yrs you've gotten you money's worth out of them (really, you have) and replace them with a set of Spicer U-joints. If someone here has a better brand of U-joint to recommend then please speak up now, otherwise pls trust me on this one and go & SPECIFY that you want a set of *spicer* replacement U-joints, don't settle for Brand-X or another set of Lubed for life joints. Start there. If that doesn't fix it then again I refer to your post and while you've had the front wheel bearings replaced you didn't say jack about the rears, time to pony-up and replace those as well. Granted it's not as easy a job as doing the fronts but with the age and probable milage you have I would most certainly replace the rears, once again you've gotten your money's worth out of them. If U-joints and rear bearings don't make this go away (and really, I think they will) then it's time to start looking at pinion bearings or an out-of-balance shaft. Doesn't sound like you beat it so I'd put axle shafts low on the list, start with replacing the original U-joints with quality (greasable) spicers and then the rear wheel bearings. Those are the most likely candidates and also the cheapest fixes, if those don't fix it the problem is deeper & going to be more expensive but I promise that ignoring it will eventually be even MORE expensive than this.

First off thanks..Yes I triple checked and no fittings.I will get the spicers. I can't even get the dang drive shaft off..It has a ****** on both ends bolted with the head of the bolt being like a torx but not 6 points at least 12. Went to two spots already and no luck finding a socket like that.Also awhile back I bent the rear axle on the passenger side. I took it to a place and had the rear axles replaced and had a master bearing kit done. I assumed this was everything.Is there more?

 

[Broncobill78]

First off thanks..Yes I triple checked and no fittings.I will get the spicers. I can't even get the dang drive shaft off..It has a ****** on both ends bolted with the head of the bolt being like a torx but not 6 points at least 12. Went to two spots already and no luck finding a socket like that.Also awhile back I bent the rear axle on the passenger side. I took it to a place and had the rear axles replaced and had a master bearing kit done. I assumed this was everything.Is there more?

Sounds more & more like bad U-joints. Without knowing what-all is in the master kit I can't comment but if you've replaced the shafts & bearings already I'd drop them lower on the list of suspects. Any chance the housing is bent ? Yeah, those little 12-point suckers are a pain to work with, swaped U's on a friends Explorer & he had them too. Just getcha a 12-point socket and it'll come off (might be loctited as I recall)

 

[ccool416]

I will let you know as soon as I get to it. Hopefully this weekend.

 

[ccool416]

Well,I dropped the rear shaft and engaged the front wheels and went for a drive...still had vibration in the rear, not as bad. The drive shaft seamed to not have any play. It has no grease fittings and is stamped spicer..I didn't know they came with spicers?. I decided to spray it with a penetrating lubricant change the tranny and transfer case fluid and put the drive shaft back in. when I did the vibration was gone go figure.....I also bought the gear oil for the front and back...Might as well hit all the fluids while I am at it. Bye the way both the tranny and transfer case fliud looked a little burnt.