Crankshaft Pulley Damper replacement, calling jamesmartin

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Si Click

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Lincolnshire
Need to change the crankshaft pulley on my son's D90 TD5. Thanks to the advice on here we are probably going to go with the one from Turner Engineering and will swap out the front oil seal at the same time. What he and I are debating is which technique to use to remove it.
Options:
1. Use the technique in www.discovery2.co.uk. Fabricate a holding bar, protect the radiator with a steel sheet and get a 3/4" breaker bar to crack the nut. Back on with 3/4" torque wrench.
2. Put the breaker bar on, wedge it to the right and very briefly hit the starter. Back on with torque wrench.
3. The jamesmartin technique. Take off the radiator, take the nut off with an impact wrench. Back on with a battery impact wrench and some medium thread lock.

Option 1 is do-able, but we are not well equipped to fabricate a holding bar and it looks really tight, especially to fit the oil seal.
Option 2 could go horribly wrong. :eek:
Option 3 gives the best access to replace the oil seal, doesn't need a holding bar or a massive torque wrench, and is where we are leaning. But we have some questions:
Does it really work without a holding bar? High range 5th, handbrake and chock the wheels?
What torque should the impact driver be capable of? I get that using a battery driver means that you cannot over torque the bolt, but jamesmartin, what torque does your driver deliver? Would 340Nm (250 ft/lbs) be enough?
Do you need a specialist puller to get the pulley off?
 
Need to change the crankshaft pulley on my son's D90 TD5. Thanks to the advice on here we are probably going to go with the one from Turner Engineering and will swap out the front oil seal at the same time. What he and I are debating is which technique to use to remove it.
Options:
1. Use the technique in www.discovery2.co.uk. Fabricate a holding bar, protect the radiator with a steel sheet and get a 3/4" breaker bar to crack the nut. Back on with 3/4" torque wrench.
2. Put the breaker bar on, wedge it to the right and very briefly hit the starter. Back on with torque wrench.
3. The jamesmartin technique. Take off the radiator, take the nut off with an impact wrench. Back on with a battery impact wrench and some medium thread lock.

Option 1 is do-able, but we are not well equipped to fabricate a holding bar and it looks really tight, especially to fit the oil seal.
Option 2 could go horribly wrong. :eek:
Option 3 gives the best access to replace the oil seal, doesn't need a holding bar or a massive torque wrench, and is where we are leaning. But we have some questions:
Does it really work without a holding bar? High range 5th, handbrake and chock the wheels?
What torque should the impact driver be capable of? I get that using a battery driver means that you cannot over torque the bolt, but jamesmartin, what torque does your driver deliver? Would 340Nm (250 ft/lbs) be enough?
Do you need a specialist puller to get the pulley off?
impact gun is difficult with the the air con condenser, but one of these will undo the nut and retighten in you shouldnt need a puller
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ps if its a defender then impact gun is the way to go with stud lock,just hold the gun a few seconds after its tight to ensure its tight
 
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It is a Defender and with cash tight it comes down to buying a decent battery impact gun (capable of 340NM) which will be very useful, or a 3/4 torque wrench, which will occasionally be useful. Your impact gun plan sounds fine, but I don't know how powerful your impact gun is. Obviously I don't want it coming loose, so I'm just looking for reassurance that a Milwaukee 340NM impact gun with stud lock is a sensible way to go.
 
Just my opinion!
So all you happy days fans chill!
Milwaukee, is fine if you are an electrician, but its not really garage stuff!
I have this, 950nm breakaway Torque, It has never not undone anything, only ever used it on level 3 twice.
I prefer the hog ring, over the detent ball.
You could crank a diesel loco with this, its scary and like the budgie ....cheap!
Screen Shot 2019-07-25 at 23.17.52.JPG
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I did mine as per the D2 website with a tool plasma cut to my design and a flipping great big 3/4” drive torque wrench. It’s really, really, really tight. I guess what you’re suggesting is you do it up with the gun and assume it’s tight enough? If JM thinks that’s ok I would guess it is, I’d sleep easier knowing I’d torqued it correctly though.
 
The bolt came out OK. The Milwaukee was not upto the job, but it is probably fine for most things and is tiny, so very usable in tight spaces. At just over £200 with battery and charger, I'm happy with the purchase.
https://www.screwfix.com/p/milwauke...ithium-brushless-cordless-impact-wrench/482hf
The DeWalt looks excellent, but is about the same size as a mains powered one - which is much cheaper.
We tried the 3/4 breaker bar and crank the engine technique. Surprisingly safe, but doesn't work, the starter motor does not have the torque required.
In the end we replaced two of the three bolts and used them to wedge a 1/2" breaker under the chassis and then just undid it with a 3/4" breaker and some applied muscle. The damper pops right off, no need for a puller.
We have gone with a replacement from Turner Engineering, together with a new oil seal and bolts - just over £200 inc VAT.
 
I did mine as per the D2 website with a tool plasma cut to my design and a flipping great big 3/4” drive torque wrench. It’s really, really, really tight. I guess what you’re suggesting is you do it up with the gun and assume it’s tight enough? If JM thinks that’s ok I would guess it is, I’d sleep easier knowing I’d torqued it correctly though.
if a bolt is tight its tight and so wont undo ,torque and exact bolt stretch is important with situations were even clamping pressure is vital ie heads or pipe flanges in high pressure lines etc,once a bolt is nipped there perhaps 90 degrees before its really tight ie stretched, no one should buy a 3/4 torque wrench i dont know any than ever have for cars and landies
 
The bolt came out OK. The Milwaukee was not upto the job, but it is probably fine for most things and is tiny, so very usable in tight spaces. At just over £200 with battery and charger, I'm happy with the purchase.
https://www.screwfix.com/p/milwauke...ithium-brushless-cordless-impact-wrench/482hf
The DeWalt looks excellent, but is about the same size as a mains powered one - which is much cheaper.
We tried the 3/4 breaker bar and crank the engine technique. Surprisingly safe, but doesn't work, the starter motor does not have the torque required.
In the end we replaced two of the three bolts and used them to wedge a 1/2" breaker under the chassis and then just undid it with a 3/4" breaker and some applied muscle. The damper pops right off, no need for a puller.
We have gone with a replacement from Turner Engineering, together with a new oil seal and bolts - just over £200 inc VAT.
you only have to look at battery size to see it wouldnt be upto the job
 
you only have to look at battery size to see it wouldnt be upto the job

I need to finish the job on Saturday. So, I can torque to 340NM with stud lock and cross my fingers. From JM's post that now seems like a bad plan. Or,
I can try to find somewhere local to buy a 3/4" torque wrench. Or,
I can torque it to 340NM without stud lock and then use a 3/4" breaker bar to properly tighten it - say another 30 degrees of rotation.
I am assuming that this is a bolt that would be really difficult to overtighten. In which case I am fairly relaxed about using a breaker bar on it.
 
I need to finish the job on Saturday. So, I can torque to 340NM with stud lock and cross my fingers. From JM's post that now seems like a bad plan. Or,
I can try to find somewhere local to buy a 3/4" torque wrench. Or,
I can torque it to 340NM without stud lock and then use a 3/4" breaker bar to properly tighten it - say another 30 degrees of rotation.
I am assuming that this is a bolt that would be really difficult to overtighten. In which case I am fairly relaxed about using a breaker bar on it.
yes just a bar you cant over tighten it unless you go for a 10ft bar , a bolt just needs to nipped up then few degrees for stretch
 
I was able to borrow a very nice britool one, was close to making a purchase though. Did buy a 3/4 breaker but also got a wheel nut socket to go with that so it now lives in the car.

The tool was 900mm long, torque wrench probably about 1m. It took everything my dad and I had to get the wrench to click, crazy tight. What you’re saying makes a lot of sense, I get a little carried away with trying to do things by the book I guess. Mine is a turner engineering item too, hope never to have to do that particular job again!
 
RAVE says to use a torque multiplier so I'm wondering why this method wasn't suggested here. I haven't had the need to remove the crank pulley bolt yet so I'm curious if there are any restrictions to use a torque multiplier for this job.I use one to do the wheel hub stake nuts (490Nm) and it makes life so much easier every time.
 
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All back together. Removing the oil seal was more tricky than I imagined as it was well and truly solid. Eventually got it out by tapping one side until the other side popped clear. A 48mm socket was ideal for tapping the new one in.
The engine started first time and ran very sweetly while I bled the coolant........then when we started it again it stopped as soon as the key was released. Damn ignition barrel chose this point to fail and won't stay at position II. That will be a new barrel and door locks then.:rolleyes:
 
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