Crankshaft Pulley Bolt Removal

[mikeydude]

Nice long substantial tool you got there!

ow ,...er missus...

[texas2201]

Ditto - but I am now stuck at the tensioner and idler pulleys - watched the video on the M100 channel and he says the bolt is 10mm multi spline.......I thought he meant a torx but even an E14 will not fit and I do not have an E16? Does anyone know what kind/spec of socket fits these "star" bolts

Oliver,
These photos might help. I replaced my timing belt last weekend.

The main points are:
- Make up a bracket as shown to lock the pulley.
- Undo the lowermost engine mounting bolt (shown in the bracket photo and just visible in one in-situ photo) and then replace it to bolt on the bracket.
- Use two short (about 2cm) M6 bolts (edit to correct to M6 from M5) through the bracket to locate in the holes in the pulley.
- The pulley now is not going anywhere.
- Use as many extension bars as needed (about 15 inches) and an extremely long lever handle.
- Note the use of an axle stand at the fulcrum.
- Lean on the handle very hard (it is normal right-hand thread - ie unscrew anti-clockwise).
- Use only a good quality socket, as my picture shows what happens to a socket which is part of a cheap set which has done me OK for the past 30 years. Halfords Professional is OK.

Good luck,
John

John,

I owe you another pint - I followed your guide to the letter and I got the pulley off this evening!

Thanks

Jim

[dapinky]

Martin,

As far as i know it is just a 'standard' 12-point M10......

.... at least, that is what I have always undone the idler bolt with.

The torque figures quoted for it are a bit misleading though - I think I've always had to use some form of extension piece to crack the bolt off - I have used a ring spanner with a tube over it, and I have used a 3/8" socket (I think it was the only 12 point 10mm I had!).

[texas2201]

Thanks Dave - tried a ring spanner and broke it...... going to try a 3/8 12 spline M10 socket

[dapinky]

The annoying thing is that once you've cracked it off, it will undo with your fingers! (on my 1st Elan I tried to undo it with the head on the bench - I couldn't hold it down and apply enough force to the bolt at the same time. I ended up knackering the bolt head, so i ground it off, took off the idler and expected to need some sort of tool/mechanism to remove the remaining stud - but it was so loose that i could just do it with my hand)

It takes a certain amount of confidence to try to remove the bolt head with the cylinder head in situ though - you'll always be thinking "what will i do if i can't get it out??"

[texas2201]

The annoying thing is that once you've cracked it off, it will undo with your fingers! (on my 1st Elan I tried to undo it with the head on the bench - I couldn't hold it down and apply enough force to the bolt at the same time. I ended up knackering the bolt head, so i ground it off, took off the idler and expected to need some sort of tool/mechanism to remove the remaining stud - but it was so loose that i could just do it with my hand)

It takes a certain amount of confidence to try to remove the bolt head with the cylinder head in situ though - you'll always be thinking "what will i do if i can't get it out??"

Yikes.....

Did anyone ever find replacements for these bolts?

[Brit-Car-Nut]

The annoying thing is that once you've cracked it off, it will undo with your fingers! (on my 1st Elan I tried to undo it with the head on the bench - I couldn't hold it down and apply enough force to the bolt at the same time. I ended up knackering the bolt head, so i ground it off, took off the idler and expected to need some sort of tool/mechanism to remove the remaining stud - but it was so loose that i could just do it with my hand)

It takes a certain amount of confidence to try to remove the bolt head with the cylinder head in situ though - you'll always be thinking "what will i do if i can't get it out??"

Yikes.....

The Tensioner Bolts are GM # 94329851. I don't know if these are 12 point or 6.
The Idler Bolts are GM # 94443429. I don't know if these are 12 point or 6.

If you mean the crankshaft pulley bolt, it is GM # 94123580

[Saltire]

The annoying thing is that once you've cracked it off, it will undo with your fingers! (on my 1st Elan I tried to undo it with the head on the bench - I couldn't hold it down and apply enough force to the bolt at the same time. I ended up knackering the bolt head, so i ground it off, took off the idler and expected to need some sort of tool/mechanism to remove the remaining stud - but it was so loose that i could just do it with my hand)

It takes a certain amount of confidence to try to remove the bolt head with the cylinder head in situ though - you'll always be thinking "what will i do if i can't get it out??"

Yikes.....

If you mean the tensioner and Idler pulley bolts, then yes.

They are GM # 94002482. these are the 12 point bolts like the M100 uses.

Isuzu's parts book shows the part number 8944434291 which is a 6 point bolt and not the 12 point like Lotus and GM. Maybe they are for the non-turbo 1.6L model?

If you mean the crankshaft pulley bolt, it is GM # 94123580

And the bad news is, the crank bolt is unobtainable - as I found when I wanted to replace my crank pulley a month or so ago. What’s worse, the replacement offered by SJs appears to be made of best quality Wensleydale:

5289E788-B8A2-4713-B3C9-39B28801FE57.jpeg

And no, I didn’t over torque it

[texas2201]

If you mean the tensioner and Idler pulley bolts, then yes.

They are GM # 94002482. these are the 12 point bolts like the M100 uses.

Isuzu's parts book shows the part number 8944434291 which is a 6 point bolt and not the 12 point like Lotus and GM. Maybe they are for the non-turbo 1.6L model?

If you mean the crankshaft pulley bolt, it is GM # 94123580[/quote]
And the bad news is, the crank bolt is unobtainable - as I found when I wanted to replace my crank pulley a month or so ago. What’s worse, the replacement offered by SJs appears to be made of best quality Wensleydale:

5289E788-B8A2-4713-B3C9-39B28801FE57.jpeg

And no, I didn’t over torque it [/quote]

That is appalling......

Checked various sites for the 12 point one from GM and all but one say it is no longer available waiting to hear from the last one if they still have any in stock:-(

[Brit-Car-Nut]

I made a few calls over here and thus far everyone says they are obsolete.

I will pursue this later today when the rest of the US wakes up.

I have a few core engines that probably have decent used bolts for anyone that might have broken or otherwise damaged any bolt.

They are just sitting in one corner of the shop.

[Brit-Car-Nut]

After I went over to the shop to remove a few tensioner and idler bolts, it became apparent that they are NOT the same length. The tensioner bolt is longer.

The corrected part numbers are:

The Timing Belt Tensioner Bolts are GM # 94329851. I don't know if these are 12 point or 6.
The Timing Belt Idler Bolts are GM # 94443429. I don't know if these are 12 point or 6.
The Crankshaft Pulley Bolt is GM# 94123580.

New ones seem to be impossible to find.

I am sorry for any confusion I caused.

[texas2201]

After I went over to the shop to remove a few tensioner and idler bolts, it became apparent that they are NOT the same length. The tensioner bolt is longer.

The corrected part numbers are:

The Timing Belt Tensioner Bolts are GM # 94329851. I don't know if these are 12 point or 6.
The Timing Belt Idler Bolts are GM # 94443429. I don't know if these are 12 point or 6.
The Crankshaft Pulley Bolt is GM# 94123580.

New ones seem to be impossible to find.

I am sorry for any confusion I caused.

thanks for trying - I cannot find any either.... SJS say they have some but wont confirm until you order? and over £5 plus postage for one bolt.......

got a 12 spline 10mm socket and very carefully got mine out - once cleaned up bolts look OK

tomorrow starts the rebuild.....

[GeoffSmith]

Glad you got it out safely but any chance you could take some pictures and measurements before it goes back in?

[Brit-Car-Nut]

I found a few of each 100E6209, 100E6210, 100E6212, 100E6215, 100E6241 and 100E6311 all new.

There are only 2 or 3 of each one, but they will be a good place to start finding a suitable replacement.

I will have them in around a week.

I also have all of them (and lots of other engine hardware) in used condition - from the used engines I have scrounged.

After I went over to the shop to remove a few tensioner and idler bolts, it became apparent that they are NOT the same length. The tensioner bolt is longer.

The corrected part numbers are:

The Timing Belt Tensioner Bolts are GM # 94329851. I don't know if these are 12 point or 6.
The Timing Belt Idler Bolts are GM # 94443429. I don't know if these are 12 point or 6.
The Crankshaft Pulley Bolt is GM# 94123580.

New ones seem to be impossible to find.

I am sorry for any confusion I caused.

thanks for trying - I cannot find any either.... SJS say they have some but wont confirm until you order? and over £5 plus postage for one bolt.......

got a 12 spline 10mm socket and very carefully got mine out - once cleaned up bolts look OK

tomorrow starts the rebuild.....

[texas2201]

[quote="GeoffSmith"]Glad you got it out safely but any chance you could take some pictures and measurements before it goes back in?[/quot

sure what pictures do you want me to take and what measurements?

[texas2201]

Question for those who have done this job before...the Rockauto kit came with three brown plastic seals? What are they for?

[Brit-Car-Nut]

I am assuming they are the two camshaft front seals and the crankshaft seal.

If your seals are not weeping, I would put them aside for the time you might need them.

[texas2201]

[quote="Brit-Car-Nut"]I am assuming they are the two camshaft front seals and the crankshaft seal.

If your seals are not weeping, I would put them aside for the time you might need them.[/quote

thanks - no weeping - i will save them for next time

[riksit2000]

Hi all, is there any issue with using a standard hex head 10mm flanged 10mm bolt, 1.25 pitch, 10.9 high tensile. I notice that SJS is selling a hex head tensioner bolt, but a 12 spline idler bolt. Surely nothing flash about these?
Cheers
Richard

[Simon_P]

any issue with using a standard hex head 10mm flanged 10mm bolt, 1.25 pitch, 10.9 high tensile.

Several issues - The engine uses lots of Japanese spec metric bolts so using the head (spanner) size can be misleading. 12 point heads are often used for high tensile applications and special bolts. If they could have used a standard bolt they would and it would have been a lot cheaper.

You will need to measure the actual thread size, look up the torque, then compare to a torque chart for that size of thread to cross reference the grade. I'll guess that 10.9 isn't man enough for the job and a standard bolt isn't sufficiently high quality/accuracy to do the job - think of the consequences of it failing.