Well, as we were saying over in the "Next QLD Run " thread, theres been a little talk about my gearbox, so I thought I'd continue in its own self important thread
So I went down to Jeep this morning and after a little look see and a bit of a drive around, it was thought that the vibration and grinding feeling is actually the exhaust system banging on either the transmission itself or the body when you put the engine under load, apparently the engine and gearbox get a little twist and that contacts the exhaust system. I only had the noise in reverse, but, after leaving Jeep, it started coming in and out going forwards, just as I would start to load up the engine giving it a bit of gas (not putting my foot down or anything, just not when coasting along).
Sooooooooo.... I stopped in at the place I had the exhast done and they said yes, it does seem to have a little play in it and they coulod see where it had been bagging against the feul tank skid , so, yes there may be some contact there, but is it enough to make me think that there is something amiss with the gearbox......I'll find out Saturday wheen I 'm booked in to have the exhast re-hung with a few bends to clear it away from anything. So after that, hopefully all with be perfect again
Still, I asked about the shudder I get when I'm on a steep downhill incline, and they thought it was the same thing, so I'll get the engine and gearbox mounts checked as well, because if I'm getting that much movemnt, something may be wrong there????.
Been doing a bit of asking about the reverse gear and not going anywhere issue that you guys have had as well.
stevemcc wrote:
Sorry to read that you've got problems and I hope that its nothing major....
I have to ask if there were any initial signs? Mine has gradually been getting worse in reverse, even when I swap back to the 'little' tyres. Slow, load type work eg. backwards up a slope just goes nowhere regardless of revs.
Best of luck
Seems that it is part of the torque control the car has. In 2wd if you are on a bit of a steep incline (the exit of my driveway is where it mostly can happen to me) the ECU limits the power the torque converter will transfer from engine to gearbox to "not overload" the gearbox/driveline, as we have seen, you can basically stop, have NO wheel spin and you can put your foot to the floor and the engine will not rev over 2000rpm, you still don't get wheel spin (if you are on reasonable solid ground) the ECU is "limiting" everything. And remember with the bigger tyres most of us are running that also adds more resistance, thus the ECU limits even more power. Yes, I know that we would simplily prefer it gave us more when we put our foot down, but, its not designed that way. Mostly happens to mine when its cold, and Yes, when you put it in 4Hi you have no worries, mainly because the ECU has a different set of torque parameters that do not limit the driveline as much, because the drive is also going to the front it knows it can allow more power through the transmission. And again when we select 4Lo, a different set of parameters are used which pretty much don't limit the power at all. Once you understand that this is how they designed the system to work you realise that yours is not so much not working as, It is working properly, the way it was designed. I myself have found that just driving around in 2wd the grearbox still at times hunts around the gears, jumping down inappropiately at times, not as bad since I did the "pinion reset" but, still in around the 60kph area , what I decribe as "a little indecsive" now, when I put it into 4Fulltime (safe for on road as its just really all wheel drive) the ECU uses a different set of parameters for the gearbox and it seems to hold in gear much much better, when going up a slight hill it "holds" the gear longer before just going into top, locking up the torque converter and then struggling because its in too high a gear (what normally happens in 2wd) then having to do a big change down and revs go through the roof, in 4 Fulltime, it holds the lower gear all the way up the hill, and only after a really back off when at the top of the hill does it go up to Top gear. Another little trick I have found is with the accellerator pedal, when you are starting to go up a hill, and you just keep putting you foot down further and further, you may find the car just seems to not be going any faster, you can hear that the torque converter has locked up and the car just stays in top gear and struggles slowing down as it goes, then, all of a sudden it does the big change down in gears and revs and off you go...., well....instead of just putting your foot down when you hear the car starting to labor a little just slightly lift your foot on the pedal for a moment, that will unlock the torque converter and the gearbow will acually drop down a gear and pull up the hill a lot better and without all the fuss. Just a tip thats, works every time for me, you'll see your taco just rise up a little thats the torque converter unlocking. Most of this is because of the larger tyres and the gearing, thats why I have a had a conversation with a guy this moring about the 4.11 gears, they will bring the ratios back to standard with the 31' tyres so it will be like driving a standard KJ again. Hoping its not going to cost tooo much, but, thinking that with the correct ratios, feul economy will also increase as I won't be wasting power turing over too high a gear all the time, so should pay for themselves.
Hope that helps some and lets you know where I'm at with mine. I'll keep updating here on events as they happen
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Hopefully that means all good news for you. I very interested in the effect on fuel consumption. I will keep watching this space!! 
, looks like I have a fair amount of play in the control arms and the front diff seems to be easy to move around. May have done a mount or bolt or something, will have a good look tommorow morning.
