V8david Posted June 23, 2008 Share Posted June 23, 2008 Hello all. When I drive on the motorway, or at the, er, national speed limit on normal roads, i.e 60-70 MPH, when I ease off the gas and allow the vehicle to slow, I'm getting a vibration from underneath. If I put my foot back on the accelerator it stops again. Now I'm thinking it's propshaft UJs? Any thoughts? I'm replacing them soon and I was wondering if the vibration could be from the prop shafts being out of balance? Again, any thoughts? Should I get the shafts checked and balanced while they're off anyway? Where or who can check and balance them? Need someone in the Hereford area. Does Disco Al know anyone? RRC 1989 3.5 Efi. Cheers David Quote Link to comment Share on other sites More sharing options...
bishbosh Posted June 23, 2008 Share Posted June 23, 2008 Sounds like prop shafts to me. Is the truck lifted? If so I would suspect the front prop. Quote Link to comment Share on other sites More sharing options...
V8david Posted June 23, 2008 Author Share Posted June 23, 2008 Sounds like prop shafts to me. Is the truck lifted? If so I would suspect the front prop. No, not lifted, but definitely sounds like props. Cheers for the 2nd opinion bishbosh. Quote Link to comment Share on other sites More sharing options...
Highway_Star Posted June 25, 2008 Share Posted June 25, 2008 Drop the props, I'll wager you'll find one or both sliding joints aint sliding no more. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 25, 2008 Share Posted June 25, 2008 Easy to tell by dropping one or the other prop and driving about in difflock for a bit. Check sliding joints and UJ's for play / smooth operation. Quote Link to comment Share on other sites More sharing options...
V8david Posted June 25, 2008 Author Share Posted June 25, 2008 Thanks for the advice guys. I'll drop and check as soon as I can. No difflock on my old girl though. If the sliding joints aren't sliding anymore does that mean new props? Quote Link to comment Share on other sites More sharing options...
Highway_Star Posted June 25, 2008 Share Posted June 25, 2008 In my experience, yes. Or sending it to one of those prop shaft repair places and having it overhauled. I think water gets under the coating on the male splines, swelling it and tightening up the joint. I once had the exact symptoms you describe, as you go through the null point from drive to overrun, a loud humming vibration. Put the toe down again and you drive through it. At a steady speed it hums and goes along with undulations in the road (What's happening is the suspension raises and lowers slightly, so the prop length should alter, but it can't, so the diff/transfer box is under end load that shouldn't be there. Possibly also the prop flexes slightly under compression and goes out of balance. Turned out to be the rear prop shaft sliding joint, er wasn't. I did attempt to strip and clean it, it took the hi-lift to split the sliding joint, and there was no way it was going back together. Normally they come to bits/go together with a bit of muscle at the most. It's actually worth stripping them out and thoroughly greasing on a semi-regular basis, the grease nipple only really gets grease to a handful of the splines. Doing it the hard way makes sure all of them get lubricated. Quote Link to comment Share on other sites More sharing options...
therealboss Posted June 25, 2008 Share Posted June 25, 2008 If its the UJ's you should see that if you get under the truck and inspect them, if it is the UJ's do them sooner rather than later or you will pay for it. When the UJ falls apart at speed it will damage the underside of the truck and for the sake of 10 pounds per joint it just not worth it. (plus you will need a change of underpants if it fails under speed. To replace the UJ's should take you an hour or so per prop, depending on what tools you have. Quote Link to comment Share on other sites More sharing options...
V8david Posted June 27, 2008 Author Share Posted June 27, 2008 Cheers guys. I'll get the bits ordered and get them sorted. Only problem is if I order all the UJ's and it turns out to be knackered sliding joints beyond repair, I'll then want new/repaired propshafts! May save the bother and just get a couple of new shafts. I reckon if I'd been spinning around under a car since 1989 I'd be pretty knackered to Quote Link to comment Share on other sites More sharing options...
V8david Posted March 9, 2009 Author Share Posted March 9, 2009 Just to add to this, I replaced the props and still getting the vibration. It's like a loud humming vibration, if I go to 60mph or 70mph and take my foot off the accelerator it starts. As the car slows I get this humming, like a grinding sort of humming, back on the gas and it stops. So my question is what else can it be? Are there bearings in the BW transfer box? If so how do you and how hard is it to replace them? Failing that it could be a bearing in the diff. Any more thoughts much appreciated. Cheers. Quote Link to comment Share on other sites More sharing options...
sparg Posted March 9, 2009 Share Posted March 9, 2009 Hi - what's it like if you stamp on the gas? - is it only on overrun, or is there something similar under acceleration? - also, is it only there in top gear at speed, or is there a mini-version in any other gear? Quote Link to comment Share on other sites More sharing options...
V8david Posted March 9, 2009 Author Share Posted March 9, 2009 Hi - what's it like if you stamp on the gas? - is it only on overrun, or is there something similar under acceleration? - also, is it only there in top gear at speed, or is there a mini-version in any other gear? Hi sparg. It's only in top gear yes. Just as I ease off the gas and the car starts to slow down naturally, doesn't happen if I ease off in lower gears. Not there if i stamp on the gas. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 9, 2009 Share Posted March 9, 2009 If you get underneath, can you waggle any of the prop flanges where they bolt to the transfer box or the diff? A loose bearing in any of those (eg not in the prop but supporting the flange itself) could cause that. For the front of the back prop you'll need the handbrake off and wheels chocked or you won't be able to waggle it Quote Link to comment Share on other sites More sharing options...
V8david Posted March 10, 2009 Author Share Posted March 10, 2009 If you get underneath, can you waggle any of the prop flanges where they bolt to the transfer box or the diff? A loose bearing in any of those (eg not in the prop but supporting the flange itself) could cause that. For the front of the back prop you'll need the handbrake off and wheels chocked or you won't be able to waggle it Cheers FridgeFreezer, I shall have a waggle today and report back! Quote Link to comment Share on other sites More sharing options...
disco_al Posted March 10, 2009 Share Posted March 10, 2009 i was about to suggest the u/j's, having just done my front prop over the weekend. but it sounds a bit more involved than that. as for getting them reconned, try allspares, as they have a prop recon service, but it costs around the £100 mark from memory - although as LR's use fairly standard joints it may be a lot less. check the prop flanges for play, maybe some slack appearing there? what were the joints like on the props you removed? Quote Link to comment Share on other sites More sharing options...
V8david Posted March 10, 2009 Author Share Posted March 10, 2009 Right, I have had a waggle about under the truck today and here's where I found some play... The sort of flared bit (arrowed) that sticks out of the transfer box is where there is visible play when I waggle the prop. There is no play at either diff, the rear of the transfer box feels like it's got similar play at the output but I can't see because of the handbrake drum. Another thing about the vibration... When it's in full swing at speed it gets louder if the car bounces over a bump in the road (smooth bump rather than harsh, like a dip in a motorway, so the car bounces). As the car naturally bounces the vibration sounds louder then quieter, seems to vary while articulating. Once the car settles it's back to normal, until the speed drops enough or I re-apply the gas. Another way of getting it to vibrate is hitting a pot hole or manhole cover at the correct angle. This happens around 30 mph and it's a much shorter vibration but sounds the same. Thanks for the info Al, joints were good on the old props. If anyone's in the Hereford area with a Borg Warner transfer box on their truck that they don't mind me waggling about a bit it would be much appreciated. Just so i've got something to compare mine to. Quote Link to comment Share on other sites More sharing options...
disco_al Posted March 11, 2009 Share Posted March 11, 2009 how much wiggle is there? IIRC from another thread on props, about 3-4mm of play is fine in that bearing, as it's a standard ball race, not a taper bearing. that's the prop output bearing, i did find a thread on how to replace it without removing the trans box somewhere..... bearings are quite cheap, IIRC £10 from Bearmach Quote Link to comment Share on other sites More sharing options...
V8david Posted March 11, 2009 Author Share Posted March 11, 2009 how much wiggle is there?IIRC from another thread on props, about 3-4mm of play is fine in that bearing, as it's a standard ball race, not a taper bearing. that's the prop output bearing, i did find a thread on how to replace it without removing the trans box somewhere..... bearings are quite cheap, IIRC £10 from Bearmach Cheers Al. Sounds good to me. I'll have a search round for the thread. Can't think of anything else it could be. To answer your question there's a small amount of wiggle but it's visible, can't just feel it I can actually see it. That's why I need to compare it to someone elses. I'll dive under the next RRC I see and have a waggle. Quote Link to comment Share on other sites More sharing options...
V8david Posted March 11, 2009 Author Share Posted March 11, 2009 I've had a look for the output bearing replacement thread. Seems to be the LT230? Is it the same sort of procedure for the Borg Warner? Or is that a completely different arrangement? What Tbox have you got Al? As you may be able to tell, I know absolutely f*ck all about transfer boxes! Well the inards of them anyway... Quote Link to comment Share on other sites More sharing options...
disco_al Posted March 12, 2009 Share Posted March 12, 2009 ummmm, 5 spd manual on mine, thinks it's the lt230? the thread i found was on www.discoweb.org loads of useful info on there. i would imagine that the procedure would be the same for manual/auto. Quote Link to comment Share on other sites More sharing options...
knudsen Posted March 14, 2009 Share Posted March 14, 2009 Right, I have had a waggle about under the truck today and here's where I found some play... The sort of flared bit (arrowed) that sticks out of the transfer box is where there is visible play when I waggle the prop. There is no play at either diff, the rear of the transfer box feels like it's got similar play at the output but I can't see because of the handbrake drum. Dear David, a little side play there is normal. No more than maybe .050" though. You have to have a feel for it. Waggle it, then go to another rangie and waggle that one. They should both feel the same. Check the RAVE manual, as there is a method to change the seal with the case still in place. Cheers mate. Quote Link to comment Share on other sites More sharing options...
V8david Posted March 15, 2009 Author Share Posted March 15, 2009 Dear David, a little side play there is normal. No more than maybe .050" though. You have to have a feel for it. Waggle it, then go to another rangie and waggle that one. They should both feel the same. Check the RAVE manual, as there is a method to change the seal with the case still in place. Cheers mate. Cheers knudsen, that sounds like quite alot of allowable play. You're right, I'll dive under the next RR I see and waggle theirs. Will check out RAVE as well... Quote Link to comment Share on other sites More sharing options...
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