[john.harrill]

Update

Four things to report:
1. The serpentine belt tensioner 'shock absorber' is cracked at the upper boss. It will have to be replaced.

2. I can see the timing marks on the cams from the last time the belt was changed. The front head's mark line up adjacent to each other, but the rear head's do not. The rear exhaust cam has slipped at least two teeth.

3. I'm having a hard time seeing the TDC pointer on the engine. Where is it on the block?

4. The two pin holes that the tension tool fits into are rotated to almost the top of the tensioner wheel. The tool cannot be assembled in such a way as to have the arm parallel to the ground. Also, where is the hole for the rig pin?

 

[Alfisto Steve]

Four things to report:
1. The serpentine belt tensioner 'shock absorber' is cracked at the upper boss. It will have to be replaced.

2. I can see the timing marks on the cams from the last time the belt was changed. The front head's mark line up adjacent to each other, but the rear head's do not. The rear exhaust cam has slipped at least two teeth.

3. I'm having a hard time seeing the TDC pointer on the engine. Where is it on the block?

4. The two pin holes that the tension tool fits into are rotated to almost the top of the tensioner wheel. The tool cannot be assembled in such a way as to have the arm parallel to the ground. Also, where is the hole for the rig pin?

1. If you get a new one it hopefully will come retracted with rig pin holding it compressed. Leave it compressed when you install it.

2. Then three of the foor timing dies should fit and crank pulley shold be at TDC.

3. It is not actually on block but front cover about 11:00 position. As I said it looks like a triangle pointer and at TDC notch on face of crank pulley splits between two teeth and you want that pointer to split teeth and match line in pulley.

4. Maybe try rotating adapter with two pins in it 180 degrees to get pins on top or loosen bolts holding adapter to weighted arm as arm at adapter attach point has half moon slots to raise or lower arm on adapter to make weighted arm parallel.

Rin pin holes for 1/16" drill rod are in tensioner piston housing and small chrome pistion not in tensioner eccentric arm or tensioner pulley that weighted tool pins go into. You have to remove PS pump pulley, PS pump bracket that goes to accessory belt tensioner bracket and then remove accessory belt tensioner and bracket assembly to really see TB tensioner with its rig pin holes (tensioner looks like a lower case letter t and is about diameter of a cigar).

If air gap between tensioner housing face end that piston sticks out of and face of eccentric arm is not 1/8" and if 1/16" drill rod rig pin does not insert freely into tensioner housing go through hole in piston and out the back side of tensioner housing then timing belt is not tensioned correctly.

On Myrons 24v I found rig pin hole way off (piston extended to far) and air gap about 1/4" and eccentric arm almost frozen to pivot pin so there was not real tensioner movment keeping belt in proper tension as engine expanded and contracted when going from hot to cold or cold to hot.

I had to remove tensioner put it in vise and very very slowly compress piston so I could insert 1/16" rig pin. Then I had to remove snap ring and fight to get tensioner eccentric arm off stud on front of block. Then I had to use a gun barrel brass cleaning brush to ream out crud so it would move freely after I also polished stud.

I also had to hold cam pulley of cam that was out of time, loosen nut, knock pulley loose off cam end, rotate cam to get fouth timing die on.

Then I found I had to leave that pulley loose to get new timing belt on all 5 cogged pulleys, two ilder pulleys , cranks shaft cog pulley and tensioner pulley before I could set belt tension by rotating eccentric to get that 1/8" air gap with 1/16" rig pin still in tensioner piston. This is where properly set weighted arm comes into play.

Hope this is not overload but until you have worked through the rigging/tensioning process and gotten correct air gap with rig pin still in piston it isn't correct.

Once you have it and all four cams still locked down then hold loosen cam pulley and retighten nut to lock pulley to taper on cam.

Then you are ready to hold weighted arm and torque down nut holding tensioner pulley to eccentric arm and prceed to recheck 1/8" arm gap. If OK you can carefully remove 1/16" rig pin from tensioner by raising or lowering weighted arm very slightly so rig pin slips out. Then rotate engine with plugs out using socket on crank and see that tensioner air gap remains correct and you can slip in and out 1/16" rig pin easily in tensioner.

It was hard for me to visualize this the first time and I had to tweak it a couple time to get it correct.

 

[john.harrill]

Yesterday's Findings

After studying the belt in place, I decided to remove it, as the goal of this operation was to replace the belt and re-tme the engine. What I found was an epiphany.

A few weeks ago, I had a mystery rattle coming from, what I thought was the top of the engine. Just as it had appeared, it vanished. Good news, right?

Wrong. Looking at the timing belt idler on the front of the engine, I could see the ball bearings inside of it. The seal on the idler wheel was missing and the idler had seized. The earlier noise was the bearing in it's last days, and when it seized, the noise went away. The jumping of one of the cams last week was probably brought on by the seized idler.

The timing belt showed signs of heat-induced degradation. I think that I may have been only a few days away from a complete belt failure.

Where I am now:

• I have located the holes in timing belt tensioner and the chrome piston. By applying very slow pressure, I can get it to move into the cylinder. I just need to find a suitable rig pin.
• The eccentric wheel bracket pivots freely, and so does the wheel itself.
• The cams are locked down. So I don't think it will be necessary to loosen the cam wheel. (By the way, the cam had jumped 2 teeth.)
• The reason I am having difficulty with the tensioner tool is that the hub is for the serpentine belt tensioner, (1820275000) not the timing belt tensioner hub (1820274000).

Does anyone know a source for the correct hub? Also, a source for the serpentine belt 'shock absorber'?

 

[Alfisto Steve]

I think I may have the correct hub in a shipment of tools I got from Difatta Friday evening but we were leaving town Saturday morning and all I had time to do was retrieve the UPS box from front porch and stash, so stay tuned.

We get back home tonight and I hope to get to open my surprise tool shipment from Italia that giovanni@difatta.com had back ordered for me.

I am so glad you opened your patient before you have a valve bending experience.

Here is a parts list of nice to change items when doing Timing Belt Change:

Duh! belt 60561244
two top idler pulley assemblies 60561649
one tensioner idler pulley assembly 60580235

Usually reuseable tensioner 60584475

As for accessory drive the tensioner cylinder assy is 60561380 "shock cylinder"
Accessory tensioner idler pulley assy 60561614
Two accessory belt idlers 60561615

Accessory belt 60618584 has a superceding part number as per a factory bulletin I think but don't have number handy now.

Hope your vendors have parts you need to order.

 

[Alfisto Steve]

As for some earlier questions I missed. The closer TDC is the better and with the timing dies holding all four cams in time you may find it neccessary to knock loose a cam pulley or two loose to get belt on all cogged pulleys.

And since cam pulleys are not keyed to cams like 12v engines you can fine tune (time) crank to perfect TDC.

I had to loosen rear head intake pulley on Myron's 95LS to even be able to get timing belt on all cogs without moving crank so expect to knock a pulley loose to get belt on. I hope 24v cam pulley wrench is one of my backordered tools in surprise shipment.

His car now starts with touch of key and idles almost water glass on head smooth but not quite as smooth as a 1927 1.5L Bugatti my friend's father in law' in JAX has but super smooth for a production line engine.

 

[john.harrill]

Parts

I just ordered the timing belt idlers from IAP. The rest will probably have to come from DiFatta......

That will get me started.

 

[Alfisto Steve]

John I got the adapter 18202740 for doing timing belt tension in that shipment and you said you have the 18202750 adapter for doing the accessory belt tension.

I put in order requests to Jason and Difatta to see who can get me a cam pulley wrench 18202720 and a 18202750 adapter. Giving up on head socket 18221210 as ePer DVD shows it out of production.

You said you had found a socket to fit head stud nuts right?

PM me about adapter, OK?

 

[velocedoc]

Ok, where am I going to get the tools for setting up the timing belt? Obviously I am short on tools, looking at the one that sets the tensioner as pictured here. Costs for these tools?

 

[Alfisto Steve]

Tools you need for 24v timing belt and cam timing job:

18202720 cam pulley and aux pulley wrench
18202730 adjusting arm and weight
18202740 adapter for 730 wgt/arm for timing belt tensioning
18202750 adapter for 730 wgt/arm for accessory belt tensioning
18708966 24v cam timing dies new number replaces 18250400

Email Giovanni Difatta at giovanni@difatta.com www.difatta.com or Jason at parts@alfissimo.com for price quotes as they can order tools.

Giovanni just sent my list to Italy this morning.

I rent out cam timing dies and will be renting 740 adapter to John he has my timing dies. I now have a second set of timing dies to rent out but only one weighted 730 arm and 740 adapter.

I do not have 720 pulley wrench yet or 750 adapter. However Johnny just got back to me and it looks like he has a source to get me them, too.

 

[velocedoc]

I am blessed that I was able to get a set of cam locks for the job, from Germany, before the value of the Euro went up. I will check with Giovanni and see what I can do to get a set of tools. Thank you.

 

[john.harrill]

Tensioner/Rig Pin Trick

The 'C' clamp trick works.
I clamped the tensioner body vertically in a bench vise. Then I placed a 5" 'C' clamp and gradually applied pressure (over 15 minutes) and the piston retracted.

I slid a 1/16" tungsten drill bit through the hole and out the back side.

Piece of cake.

 

[john.harrill]

Update:

Idlers and tensioner wheels are on the way.
Timing belt tensioner is compressed and the rig pin is in place.
New water pump is on.
Front of the engine has been cleaned.

I hope all the parts will be here by the weekend.

 

[john.harrill]

Parts Update:

I received the serpentine tensioner shock and the timing belt tensioner wheel from DiFatta.

However,
International sent the wrong timing belt idler bearings. Here's what happened:

I ordered the bearings on-line. However, the web site has the serpentine bearings listed under the timing belt bearings. They arrived, I realized the error and called IAP. I decided to keep them because I need to replace them any way. So I told them to send the correct bearings. They assured me that the bearings (Their part number 02754000) were the same for all V-6s.

They're not.

These are not Alfa number 60561649. They are smaller in diameter. So, tomorrow I'll call them again.......

A shame, really. I think I have finally grasped the process for setting the timing belt tension.

 

[Alfisto Steve]

I hate it when something like that happens. I do buy from them but for quick delivery and usually OEM correct parts I use giovanni@difatta.com as you know.

What did IAP send you two of this "one tensioner idler pulley assembly 60580235"? You said you got two smaller than top idlers.

What does this match "timing belt tensioner wheel from DiFatta"? Different that what you got from IAP?

Pictures please of your old parts and what you got new?

 

[john.harrill]

Wrong parts.

Steve,
I'll post pictures later. What they sent were 2 idlers that are about 1/2" (diameter) too small. I think they are for the 12-valve.

 

[Alfisto Steve]

But where would they be used? The 12v does not use any idlers for timing belt just tensioner with it's own pulley bearing assembly.

Serpentine belt uses one idler that is just a slight bit larger OD than 24v timing belt idlers. The 24v serpentine belt idlers are bigger OD than all of the above idlers.

Something is not computing here. Any part numbers on boxes they came in?

I bet they sent you idler for series 4 Spider serpentine belt. Are they narrower too?

 

[john.harrill]

Idlers.

That must be the case. I just got off the phone with IAP. They took ownership of the problem and are sending me a pre-paid UPS label to cover shipping the idlers back. But they do not have the correct (60561649) idlers.

I ordered them from DiFatta about 30 minutes ago. I used the Alfa part number so there would be no confusion. They should arrive late next week. What this cost me was a week's worth of time, sending the parts back and forth.

 

[Alfisto Steve]

John,

Could you lay out a photo op of your TB idlers, TB tensioner pulley and serpentine tensioner pulley and serpentine idlers plus wrong idlers you got so we can see for future reference.

If we could see comparative sizes and know OD measurements of correct and incorrect parts as we don't see much 24v stuff apart.

 

[john.harrill]

Photos.

I'll take some pics after work......

 

[john.harrill]

Here are some shots of the bearings: