| Author |
Message |
    
Lawrence Tilly (L_Tilly)
| | Posted on Thursday, February 06, 2003 - 05:38 pm: | 
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Well, the vibrations I've been getting are definetly the roto. Although it looked fine edge-on, I found the area around the bolts is coming apart (I can push a finger in next to the bolts). I'm ordering a new Rotoflex and six new bolts (mine are in the same rough shape as most of the underside of the rig) and want to be sure I'm not forgetting something or underestimating the project.
From the diagrams, looking at my rig, and some of the info I read concerning replacing the Roto w/ U-Joints, it looks like a simple swap is pretty straight forward: Remove the six nuts (19mm), compress the driveshaft to drop the old roto, insert the new one, and bolt it back up.
Am I missing something? Is this really easier than an oil-change??
Lawrence lnctilly@metrocast.net
96 Disco "Beowulf" NH, USA |
Paul T. Schram (Paulschram)
| | Posted on Thursday, February 06, 2003 - 07:13 pm: |
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Well:
I don't know that I'd say it is as easy as an oil change, but only because you have more bolts to loosen/remove.
Crawl beneath truck, at rear. Remove six nuts,bolts. Collapse driveshaft splined joint toward front of truck. Avoid falling rotoflex. Install new, tighten bolts/nuts. Drink beer!
But, if you need a new rotoflelx, you might as well pull the driveshaft and swap the universals while you're at it (some of you were waiting for me to say that, now weren't you?). If you don't need them now, yoyu will soon. Get the U-joints from NAPA, about $25 each.
Peace,
Paul |
Rick Lindgren (Slacker)
| | Posted on Friday, February 07, 2003 - 12:50 am: |
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Two other things:
1) They are supposed to be directional. i.e. The "front" of the donut should face the front of the truck. There should be little arrows on the side that show which way the bolts go through to help you put it on correctly. However this could be complete crap since I've received some rotoflex that didn't have the little arrows.
2) Be aware that the driveshaft will want to "settle" once you remove the bolts so the bolt holes won't line up if it settles very much. You could probably correct the problem by putting the t-case in neutral or jacking the back end up until the wheels spin freely but I like to avoid things like neutral and jackstands (when possible) if I'm laying under the truck cranking on a bolt. To avoid that, just make sure the wheels are well chocked so the truck isn't going to move before removing all the bolts.
All of this may just be common sense, but I was and am still very new to working on trucks so I'm passing along the forehead slappers that I've had.
Rick |
Lawrence Tilly (L_Tilly)
| | Posted on Friday, February 07, 2003 - 08:34 am: |
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Thanks, Rick. I hand't heard the settling-driveshaft tip before, but I do keep the rig well chocked when I'm under it.
I do like much of what I've heard about the u-joint conversion, but I have other things on the rig that need the extra Disco-Spending-Units more than that would. Plus, it seems to me that keeping a spare roto with me on the trail would be a cheaper and much easier field-repair than a damaged u-joint. Of course, it could be that the u-joints are so much stronger than the roto that they have little chance of failure, but then again I've not heard of a roto failure that wasn't related to normal wear anyway.
-Larry |
Brian Dickens (Bri)
| | Posted on Friday, February 07, 2003 - 10:39 am: |
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I just did this last weekend. The rotoflex itself is easy (I would say that it is as easy as an oil change). However if you have had bad vibrations and have been driving on that rotoflex long enough, the center bushing could need replacing as well. This bushing mounts in the drive shaft and is a metal cylandar with a rubber bushing inside. It is one piece and is a real bugger to get out of the drive shaft. The rubber portion on mine was toast.
I used a technique similar to that in the link below.
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Lawrence Tilly (L_Tilly)
| | Posted on Friday, February 07, 2003 - 03:51 pm: |
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Brian, would damage to the bushing be apparent, or is it more "internal"? I imagine if I get it all back together and still have vibes then I'll need to take anohter look, but it would be great if I could tell right away.
When I bought my 96 w/ 40k the auto dealer put on a new roto as part of the sale agreement. I've put over 50k on it over two years. If I can get half that out of the next one I'll be happy. I have put an OME HD lift on about five months ago, so if this next roto goes pretty quick I'll consider a u-joint switch.
-L |
Brian Dickens (Bri)
| | Posted on Saturday, February 08, 2003 - 01:23 am: |
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Should be apparent.
You should be able to inspect he bushing with a decent light while you take off the rotoflex. Look at the end of the drive shaft and see if there is damage to the rubber part of the bushing. I took off the entire drive shaft as described in the shop manual so it was easy to look at.
The link above shows wear after 6 weeks use (not good). If the rubber part is bad, you should replace (IMHO), but again it was a royal PITA for me. If you are prepared for it,then maybe its NBD. You will need some grease to refit.
If it is not too bad and you are considering u-joint swap, then there would be some trade-offs to consider. |
Lawrence Tilly (L_tilly)
New Member
Username: L_tilly
Post Number: 64
Registered: 02-2002
| | Posted on Tuesday, February 11, 2003 - 05:22 pm: |
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**** More Help, Please ****
Ok...I *Finally* got some time on this project and got the old roto off. I had to dremel one bolt that was just too damn frozen, but the others worked off. Naturally, I found that the bushings had gone bad (rubber is pretty much chewed). My roto kit came with a new one that I would be happy to put in, EXCEPT...
I can't get the old one out. I have looked at the link Brian posted above and tried a search but before I do something that could cripple my rig for even longer than it has been, I would really like to chat with someone on this process.
The driveshaft is still under the truck (I only took off the roto end) and I really prefer to work on it that way if possible (I imagine I won't be able to get the bolts off the other end without cutting several of them).
From Blue's message and pics I'm guessing he cut it from the inside of the bushing, then put a chisle in there, wacked it and pulled it out. Is this correct?
Also, what type of greese do you put in there before reassembling it? I have to pick it up since the only thing I have in the grease department is the lithium greese I use w/ the greese gun.
As always, TIA!!!
-Lawrence |
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