I am by no means the first person to tackle this job, but as there will be others to come, it’s always worth having as many references and help guides as you can get your paws on.
I would grade this as well within the capability of most home DIY mechanics. Probably a rating of ‘6 out of 10 spanners’. Very few tools needed, only special tool would be snap ring pliers. No measuring or technical stages. However, as I shall explain, there are some stages that require you to be experienced in auto problem solving. If you have won the Crystal Maze or been on Scrapheap Challenge, you’ll be fine. Either that or seek the help of an adult.
I did this with the car on the drive, not raised at all. I have listed some part numbers in the narrative. Please do not use these blindly to order parts without checking. They are just there to type into an EPC so that you distinguish between stages. Some of them have more than one part number for different sizes. I have picked these arbitrarily.
Drop the rear prop shaft. 14mm spanners. It’s worth servicing the prop whilst it’s off. I gave the yokes a good scrape out and pumped them with grease until it came out of all 4 bearings and split the sliding joint too and gave that a real clean, greasing the splines before reassembly.
Drop the oil and leave to drip for a while (do the prop in the meantime)
There are 9 x 14mm bolts holding the extension onto the transfer case. Some are long and some short. They cannot be confused. All the long ones run down the right side under the bottom and the short ones up the left side and over the top. All are easily accessible with a spanner or socket.
Disconnect the speedo plug and the two lock sensor plugs on the top of the box. The smaller of the two (angled into the box) is the one you should disconnect to enable the better low range gear changes and full control over the centre diff lock button.
The extension is on two studs so it can’t fall off. It’s not that heavy but put two long bottom bolts back in to hold it as you prise it off the transfer case. Watch out for the oil pump drive key falling out and some thin large round shim washers that might come out too. If they do, you can put them back onto the TC using the oil film to ‘stick’ them in place. What is left on the truck should look like this:
The brown is 17 years of residue.
OK this took me around 40 mins to get to this stage.
So it’s onto the bench from here.
This is what’s facing you. The small clock dial is the oil pump. Nothing to mess with there but there is a small drive key that sits in there that MUST be lined up again with its opposite slot when you come to put the two halves back together. It just turns by hand. Best just leave it be.
Now we are into the real workings. The first challenge is getting the snap ring 90520 39022 off the splined shaft. I had some long SR pliers, which were no help at all. The gap is too narrow to get the pliers in! I thought about grinding them down. The FSM says use two screwdrivers. So I did. Having grown another arm and holding a 4th screwdriver between my teeth and a 5th gaffa taped to my head, I managed to get the end of the ring lifted onto the shaft. From there it took me seconds to work it round and off. But probably 45 mins at least to get to that point. I ground down a long wood screw that was useful to get under the snap ring to stop it reseating.
This exposed coupling assembly 41330 60010 that could simply be lifted up and out. It’s several kilos. Don’t quite understand it, but it seem to be a mass damper of some sort.
Next comes a metal shield held in with 2 x 12mm head bolts. The bolt pattern is unique and can only be fitted one way. There is a third bolt to come out which does not go though the shield.
Underneath there is a thick alloy plate. The plate is a snug fit and I used 3 bolts screwed into the boltholes to lift it out. This exposes the speedo drive gear. Another snap ring; this time easy to take out with the SR pliers. Lift out the main speedo drive gear 33481 60090. It goes in splined edge upwards - just in case you forget.
Underneath, one more stupidly tricky snap ring 90521 84002 against the main bearing 90363 50005 to go and that’s it. A little tricky to get up the shaft around the secondary speedo drive gear - so don’t bother, leave it there and when you pull the shaft out it will drop off the end into the casing. When you put it back, you can get the gap in the ring around the speedo gear.
I supported the casing in the vice so that the companion flange was clear, put a long socket over the end of the shaft and whacked it once. It moved easily.
The seal, 90311 58008 came out easily. It was as hard as nails, completely inflexible and worn. Well it is the best part of 20 years old. I tapped the new one in using a roll of brown vinyl parcel tape. Perfect size.
After giving everything a real good clean and inspect, including the main bearing which seemed perfect, I put it all back together. This took me around 40 mins including seating the new seal. No mysteries at all. I have to confess that the final snap ring which took so much getting out, was placed over the splines and got pretty much rammed home using a couple of large flat screwdrivers.
Here it is all clean and reassembled. I used Wynns black RTV sealant after cleaning up both gasket faces with a steel rule. Again I used two of the long bolts to seat the casing back onto the TC. It slid together with ease. I left it whilst I put the prop back on before filling it with lovely new oil.
Went for a road test where I got 10p off a litre at Tesco. Bargain. £1.26. Eee,it were like the olden days. I'm happy, the car's happy.
Job done.
Chris
I would grade this as well within the capability of most home DIY mechanics. Probably a rating of ‘6 out of 10 spanners’. Very few tools needed, only special tool would be snap ring pliers. No measuring or technical stages. However, as I shall explain, there are some stages that require you to be experienced in auto problem solving. If you have won the Crystal Maze or been on Scrapheap Challenge, you’ll be fine. Either that or seek the help of an adult.
I did this with the car on the drive, not raised at all. I have listed some part numbers in the narrative. Please do not use these blindly to order parts without checking. They are just there to type into an EPC so that you distinguish between stages. Some of them have more than one part number for different sizes. I have picked these arbitrarily.
Drop the rear prop shaft. 14mm spanners. It’s worth servicing the prop whilst it’s off. I gave the yokes a good scrape out and pumped them with grease until it came out of all 4 bearings and split the sliding joint too and gave that a real clean, greasing the splines before reassembly.
Drop the oil and leave to drip for a while (do the prop in the meantime)
There are 9 x 14mm bolts holding the extension onto the transfer case. Some are long and some short. They cannot be confused. All the long ones run down the right side under the bottom and the short ones up the left side and over the top. All are easily accessible with a spanner or socket.
Disconnect the speedo plug and the two lock sensor plugs on the top of the box. The smaller of the two (angled into the box) is the one you should disconnect to enable the better low range gear changes and full control over the centre diff lock button.
The extension is on two studs so it can’t fall off. It’s not that heavy but put two long bottom bolts back in to hold it as you prise it off the transfer case. Watch out for the oil pump drive key falling out and some thin large round shim washers that might come out too. If they do, you can put them back onto the TC using the oil film to ‘stick’ them in place. What is left on the truck should look like this:
The brown is 17 years of residue.
OK this took me around 40 mins to get to this stage.
So it’s onto the bench from here.
This is what’s facing you. The small clock dial is the oil pump. Nothing to mess with there but there is a small drive key that sits in there that MUST be lined up again with its opposite slot when you come to put the two halves back together. It just turns by hand. Best just leave it be.
Now we are into the real workings. The first challenge is getting the snap ring 90520 39022 off the splined shaft. I had some long SR pliers, which were no help at all. The gap is too narrow to get the pliers in! I thought about grinding them down. The FSM says use two screwdrivers. So I did. Having grown another arm and holding a 4th screwdriver between my teeth and a 5th gaffa taped to my head, I managed to get the end of the ring lifted onto the shaft. From there it took me seconds to work it round and off. But probably 45 mins at least to get to that point. I ground down a long wood screw that was useful to get under the snap ring to stop it reseating.
This exposed coupling assembly 41330 60010 that could simply be lifted up and out. It’s several kilos. Don’t quite understand it, but it seem to be a mass damper of some sort.
Next comes a metal shield held in with 2 x 12mm head bolts. The bolt pattern is unique and can only be fitted one way. There is a third bolt to come out which does not go though the shield.
Underneath there is a thick alloy plate. The plate is a snug fit and I used 3 bolts screwed into the boltholes to lift it out. This exposes the speedo drive gear. Another snap ring; this time easy to take out with the SR pliers. Lift out the main speedo drive gear 33481 60090. It goes in splined edge upwards - just in case you forget.
Underneath, one more stupidly tricky snap ring 90521 84002 against the main bearing 90363 50005 to go and that’s it. A little tricky to get up the shaft around the secondary speedo drive gear - so don’t bother, leave it there and when you pull the shaft out it will drop off the end into the casing. When you put it back, you can get the gap in the ring around the speedo gear.
I supported the casing in the vice so that the companion flange was clear, put a long socket over the end of the shaft and whacked it once. It moved easily.
The seal, 90311 58008 came out easily. It was as hard as nails, completely inflexible and worn. Well it is the best part of 20 years old. I tapped the new one in using a roll of brown vinyl parcel tape. Perfect size.
After giving everything a real good clean and inspect, including the main bearing which seemed perfect, I put it all back together. This took me around 40 mins including seating the new seal. No mysteries at all. I have to confess that the final snap ring which took so much getting out, was placed over the splines and got pretty much rammed home using a couple of large flat screwdrivers.
Here it is all clean and reassembled. I used Wynns black RTV sealant after cleaning up both gasket faces with a steel rule. Again I used two of the long bolts to seat the casing back onto the TC. It slid together with ease. I left it whilst I put the prop back on before filling it with lovely new oil.
Went for a road test where I got 10p off a litre at Tesco. Bargain. £1.26. Eee,it were like the olden days. I'm happy, the car's happy.
Job done.
Chris