| Author | Message | ||
     Tom Fioretti (Tom_in_md) Member Username: Tom_in_md Post Number: 71 Registered: 02-2003 |
96D1 w/OME 2" done last fall. Replaced rotoflex 2500 miles ago and new roto-flex is disintegrating. I should have bit the bullet and went with the U-joint replacement. Where is the best place to buy the revised driveshaft with the 4-bolt flange kit ? I saw AB has a kit for $399. Where did you get yours ? | ||
| Brian Dickens (Bri) Senior Member Username: Bri Post Number: 521 Registered: 08-2002 |
If you are thinking about that kind of cash just go to great basin rovers. I just got mine and am happy so far with the results. Will give some more feeedback if you like after a week or two out in western colorado. If you want to you can shop around for an early model RRC driveshaft. Rover cannibal and other salvage places can get you the rear shaft for $100-$150 and then you need the flange kit or can shop around for that as well. If they pull the shaft, they should certainly get you the flange as well. Make sure to get a new pinion seal just in case. | ||
| Steve Rupp (Steve_rupp) New Member Username: Steve_rupp Post Number: 7 Registered: 03-2003 |
Ditto what Brian says. I bought driveshafts from another driveshaft vendor with less than satisfactory results. Bill @ GBR will give you a quality product. | ||
| Tom Fioretti (Tom_in_md) Member Username: Tom_in_md Post Number: 72 Registered: 02-2003 |
Thanks guys. I like the upgraded shaft Bill offers and placed an order today. | ||
| Federico (Fede) New Member Username: Fede Post Number: 37 Registered: 05-2003 |
I started a thread asking what the rotoflex coupler was (wasn't sure at the time) b/c I need to replace mine. I asked the same question on that thread but I was wondering what the advantages of the U-joint are over the standard? Is it worth the upgrade and $? | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 928 Registered: 09-2002 |
if by "standard" you mean the driveshaft with a rotoflex, the only known (in theory) advantage of a roto is less noise, shock, and vibrations transmitted from the rear axle to the rest of the drivetrain. Other than that, if your truck is lifted 2", in 100kmi you've bought yourself 4 rotos, at a price of brand new conversion kit. | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 929 Registered: 09-2002 |
oh, after a microsecond thought, one more thing. a rotoflex acts as a CV joint, as opposed to non-CV cardan joints (single U-joints). If you lift your truck without any compensation for pinion angle, the pinion will not be parallel to the output shaft of the transfer case. A rotoflex joint will take care of that, but will be destroyed relatively quickly. An earlier- or later-model driveshaft with two single U-joints (or conversion kit) will not compensate for variations in rate of rotation, and is more likely to cause driveline vibration. That said... I have a 96 D1 and 89 RRC with the same lift (a little under 2"), one - with a roto joint, another - with regular u-joints, and neither has vibrations. D1 eat rotos at a rate of one per year, RRC couldn't care less. Pick your poison. | ||
| Federico (Fede) New Member Username: Fede Post Number: 38 Registered: 05-2003 |
I plan on changing my shocks and springs soon also, with an OME medium duty set. I know it will lift the truck up @ 1 inch-do you think I would need to replace the rotos that often. Also would one notice a difference (noise, shock, vibration) during normal, day-to-day driving with the U-joint vs. the rotoflex? | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 930 Registered: 09-2002 |
To both questions - I don't think so. | ||
| Shaun Power (Shaunp) Member Username: Shaunp Post Number: 104 Registered: 05-2003 |
Australian disco's didn't all have roto-flexs from new. I think they started fitting them to the TDI cars in 93 to take some drive line shunt out. I have worked on 94 V8 cars that have uni's. I run a uni on my car and have no problems. Range rovers ran uni joint rear shaft from 1970 and it never caused a problem | ||
| Paul D. Morgan (V22guy) Dweb Lounge Member Username: V22guy Post Number: 1744 Registered: 02-2002 |
Ironically, Bill from GBR replied to me yesterday via email about this very same topic. He offers a replacement shaft / kit for my rear driveshaft and rotoflex assy. The higher the lift, the more stress on the rotoflex and the rotoflex is more prone to damage from ground objects. This is for a D2, but I would still contact GBR about your D1. http://www.greatbasinrovers.com/ Cheers, Paul Morgan | ||
| Brian Dickens (Bri) Senior Member Username: Bri Post Number: 524 Registered: 08-2002 |
Bills drive shafts will be much easier to maintain and reduced most of my vibes with the stock driveshafts to none. But, I am running 3" lift. Once you see a blown bushing on the end of your driveshaft where the centering pin goes (this goes through the roto), and attempt replacement of this via cutting or torching, you will like the fact that you will never have to deal with the POS again. There is no way to tell how often you will need to replace your roto based on a certain lift. It is vehicle and driver dependent. I had to replace roto about once every 1.5 years with OME HD lift. But if you accidentally hit a rock you can toast it in an afternoon. With a 3" lift I turned into a twisted hunk of rubber in the first afternoon on the trail. I really can't imagine any advantage of a roto. Sometime in '97 the stopped putting them on D1 and they are not on D2. | ||
| Paul D. Morgan (V22guy) Dweb Lounge Member Username: V22guy Post Number: 1745 Registered: 02-2002 |
"Sometime in '97 the stopped putting them on D1 and they are not on D2." Hey Brian, FYI I have the big black rubber donut on my D2. | ||
| Tom Fioretti (Tom_in_md) Member Username: Tom_in_md Post Number: 74 Registered: 02-2003 |
"Once you see a blown bushing on the end of your driveshaft where the centering pin goes (this goes through the roto), and attempt replacement of this via cutting or torching, you will like the fact that you will never have to deal with the POS again. " Amen, my Brother. | ||
| gp (Garrett) Senior Member Username: Garrett Post Number: 2195 Registered: 10-2001 |
yeh there are not hard and fast guides to knowing whether or not you have a roto under your truck. i think it was a lottery system. my '96 has one and most (if not all) of the '00's i have seen have them. and like paul said his '01 has one. the roto was designed to my knowledge to help eliminate some driveline vibes. for the most part they seem to work well on stock trucks, but once you lift them and change the angle of the shaft that all goes to shit. along with the roto. | ||
| Mike Rupp (Mike_rupp) Member Username: Mike_rupp Post Number: 234 Registered: 02-2002 |
Peter, I'm not sure I follow your logic regarding the rotoflex acting as a CV joint and reducing vibrations as the vehicle is lifted. There are two typical ways of setting up a driveshaft: 1. standard ujoints with the pinion and tcase shaft being parallel. 2. CV joint at one end (usually the tcase shaft) and a ujoint on the other end with the angle on the ujoint being close to zero. The CV joint takes care of the angle on one end to eliminate vibes, and the ujoint is not vibrating because the angle is at zero. On the rotoflex setup, when the vehicle is lifted, the angle on the tcase side will increase. Even if the rotoflex acts as a cv joint, there is still a severe angle on the tcase side, thus increasing vibrations. Even if my reasoning is flawed, it is still a moot point for me, since I was chewing up the rotoflex in no time at all. They were great for a few thousand miles, then one offroad outing, and my truck was shaking like crazy. | ||
| Greg (Gparrish) Senior Member Username: Gparrish Post Number: 1316 Registered: 04-2002 |
Garrett, I think Paul has a 2000 model, but like he said his has one. Mine is a 2001 and it has one. I haven't had problems yet, but know I'm bound to. | ||
| gp (Garrett) Senior Member Username: Garrett Post Number: 2199 Registered: 10-2001 |
yeh jens '00 with 32" tires and 2" OME lift has been fine with her roto. not sure what the magic is with some of them. i sure don't have it. | ||
| John Lee (Johnlee) Dweb Lounge Member Username: Johnlee Post Number: 285 Registered: 03-2003 |
Just a note that the D1 and D2 are different. The D2 has a rotoflex in the rear, but the angle on this rotoflex does not change as more and more lift is added. This is because the D2's trailing arms are similar to the front radius arms, i.e., the relationship between the axle and the arms does not change as more and more lift is added. This is not true with the D1's rear axle, which when dropped away from the body drops in a parallelogram-style fashion. This is why D1's with rotoflex joints and tall lifts suffer so many problems. As more and more lift is added, the angle on the rotoflex increases. This is not true with a D2. The angle between the driveshaft and the pinion does not change on the D2 as more and more lift is added. The rotoflex basically stays perpendicular to the driveshaft's centerline. This is one of the reasons the D2's can routinely accept 3" lifts without driveline vibes. | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 937 Registered: 09-2002 |
Mike, I agree with your reasoning. I don't think the D1 has a parallelogram setup, though, need to look under and see where the mounts for the upper arm are - it seems to me that the pivot line for the upper arm is aft of that for the lower arms, and the angle is different. I'd take John's word for it - he's seen the underside of a D1 more times than me. | ||
| gp (Garrett) Senior Member Username: Garrett Post Number: 2200 Registered: 10-2001 |
ahhh. very good to know john. thanks. | ||
| Greg French (Gregfrench) Senior Member Username: Gregfrench Post Number: 520 Registered: 11-2002 |
So...some 97's have a rotoflex and some don't? Is there a way to tell? What would I be looking for under there. Anybody have pics of either one so I can see if mine has it or not? If I don't have a rotoflex, then I should be good with a lift, right? Thanks | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 938 Registered: 09-2002 |
Greg, you've been driving your truck long enough, so if you don't know yet, you don't care  and that's a good thing. | ||
| Blue (Blue) Dweb Lounge Member Username: Blue Post Number: 183 Registered: 04-2003 |
http://www.discoweb.org/rotoconversion/3roto.jpg at the tail end of the rear driveshaft if you have a uj shaft, you should be fine with a little lift (~2") | ||
| Greg French (Gregfrench) Senior Member Username: Gregfrench Post Number: 521 Registered: 11-2002 |
Yes...but I want to care. Seriously, I have RTE 3" springs sitting in the back, ready to go on as soon as I get my new shocks, and would like to know if there is anything else I should do while I am under there. | ||
| Brian Dickens (Bri) Senior Member Username: Bri Post Number: 527 Registered: 08-2002 |
Whoops, sorry guys definitely learned something here I had thought that all D2 had non-roto setup. | ||
| Greg French (Gregfrench) Senior Member Username: Gregfrench Post Number: 522 Registered: 11-2002 |
Ok...I found pics in the tech section. If I don't have the rotoflex I should be ok, right? | ||
| Mike Rupp (Mike_rupp) Member Username: Mike_rupp Post Number: 236 Registered: 02-2002 |
Greg, all of this discussion is academic. You can't really predict with absolute certainty what you will need. If you have a ujoint rear shaft, you should be ok with a 3" lift. If you get vibes from the rear, you might need to get new rear links to fine tune the rear pinion angle. In the front, there's a good chance that you will have vibes. To correct that you will need a CV-joint shaft and possibly front links to correct the pinion angle (you're not looking to optimize the caster, but get the pinion angle close to zero). The bottom line is that there is usually quite a bit more work to make a 3" lift work properly. My opinion: if you are not familiar with a rotoflex, it leads me to believe that you will most likely get quite frustrated trying to get the 3" lift sorted out. Ditch the springs, get the OME and concentrate on wheeling rather than dealing with driveline issues. | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 947 Registered: 09-2002 |
Mike, exactly my point. | ||
| Greg French (Gregfrench) Senior Member Username: Gregfrench Post Number: 524 Registered: 11-2002 |
Gotcha. Thanks. | ||
| michael harrington (Mike97d1) New Member Username: Mike97d1 Post Number: 6 Registered: 07-2003 |
i have a 97 and it does not have rotos, but is there a way to tell if the u-joints are stock or if they were changed by previous owner(very unlikely). |
