cackshifter Posted July 22, 2014 Share Posted July 22, 2014 Hi, I started one of those simple things that should only take 5 minutes - a leak from the rear output flange of the transfer box. I took off the flange and realised it would have been a good idea to drain the oil. But, the oil was a funny colour, sort of rusty and cloudy. So, I drained it and thought I had better look at the input gear. That was stuck on the main shaft, but a bit leveraged persuading later, the mainshaft met my gaze. The pics show the result You get the idea. I know the wear is bad, and I know there is one solution. The question is, how much longer does anyone think it has? Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 23, 2014 Share Posted July 23, 2014 There is a sort of half way house solution as well as the replace the gearbox option. If you buy a cross drilled gear they have longer splines and will engage with the unworn splines, I ran one like that and had no noticeable wear after another 16,000 miles when checked and still no noticeable wear when the gearbox was finally swapped after it failed for a different reason another year later. There are some picture on this post http://forums.lr4x4.com/index.php?showtopic=76480&p=681087 Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 23, 2014 Share Posted July 23, 2014 In answer to the how long that R380 will last if you do nothing it's difficult to say, however the splines have actually started to break through in some of the pictures. Mine went from very worn (splines like triangles) with no breakthrough to starting to breakthrough in about 600 miles. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted July 23, 2014 Author Share Posted July 23, 2014 Yes I think if it is left, you'll get a kind of domino effect - once one goes, the stress on the rest increases, so another goes,.... then zziiiippp. Mr Wabbit, do you happen to know how much 'extra' spline the cross drilled gear has? Do they go right to the front? I do tow a horse trailer with it, so I am inclined towards safety at the moment, though I do have another Defender I could tow with. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 23, 2014 Share Posted July 23, 2014 I don't have the measurements to hand but these two pictures are taken of the non drilled and drilled gears from the end that sits next to the gearbox. Short splines Longer splines EDIT: When you think about it you don't really need a great deal of unworn spline to take the torque, you have 1.4x gearing in the transfer box and then another 3.54 in the diff. It's the hammering that is causing the break up and wear is down to lack of lubrication. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 23, 2014 Share Posted July 23, 2014 PS: You'll need the new gear when/if you get a recon box anyway so even if you decide it's not for you there is no money wasted Quote Link to comment Share on other sites More sharing options...
cackshifter Posted July 23, 2014 Author Share Posted July 23, 2014 At the moment its a 1.2 transfer box; it's behind a slightly tweaked 300tdi (big intercooler, some gas flowing, pump molestation), so the power isn't ridiculous. I do have a 1.4 so that will be going in at least for the time being, so that it has an easier time. The 1.2 box is goosed anyway, the intermediate shaft O ring leaks, and the rearmost bearing on the input gear is u/s so it has to come out. As you say the splines are on their last legs, I wonder if the gear can wobble about. Where did you get your x-drilled gear from? ( Would be really annoying to buy one only to find that particular edition didn't have the splines all the way through). Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 23, 2014 Share Posted July 23, 2014 I'm not sure of the origin of my cross drilled gear as it came in an ex mod transfer box I was fitting as my old one used to whine like nobodies business. I doubt the gear will wobble about as it's held by a taper bearing at each end. Maybe worth a ring to the supplier and get them to measure the spline length before purchase? Quote Link to comment Share on other sites More sharing options...
cackshifter Posted July 23, 2014 Author Share Posted July 23, 2014 True, I'd forgotten about the bearings (doh!). But as you say it would need reshimming, and the bearings have to be transferred over or replaced. Hmmm. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 23, 2014 Share Posted July 23, 2014 Yep it's not a perfect solution, the right thing to do is to replace the gearbox. This however is quicker, cheaper and will last a reasonable length of time, if my experience is anything to go by you'll find the gearbox will fail for some other reason before you have any other problems with the splines after replacing the input gear. Of course I am speaking just from the experience of one person. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted July 23, 2014 Author Share Posted July 23, 2014 Well, I have some other transfer boxes 'unopened'. I think first task is to open the hatches and see what is lurking inside them. If the 1.4 has a cross drilled gear then it sounds like a possible plan. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted July 23, 2014 Author Share Posted July 23, 2014 Opened up the 1.4 having scraped off a ton of grime & yippee!! it has a cross drilled gear, and it has much longer splines. So I shall go with that for now, many thanks for suggestion & sympathy Mr Wabbit. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted July 23, 2014 Share Posted July 23, 2014 That's a result! Look forward to the drastically reduced transmission slack and the ability to use the clutch with a bit less worry Quote Link to comment Share on other sites More sharing options...
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