T-III aux shaft

[shellboy]

need one asap!

[Turbo224]

Call Cindy, im sure she has them in stock.

[83scamp]

I thought all the TIII guys were going after early N/A shafts because they were stronger?

[Turbo224]

I thought all the TIII guys were going after early N/A shafts because they were stronger?

I had never heard of that. For a while I believe everyone was trying to get the chryo treated shaft and oil pump gear because they were stronger. I think the consensus now is that excessive timing belt tension and belt deflection was putting too much strain on the i shaft bearing causing it to fail. The stock i shaft will be just fine if you add the modified valve retainers and the Jackson timing belt mod.

[shellboy]

cindy is out of stock

[86Shelby]

I'm sending a short block to scrap, I can check the i-shaft to see if it's in good shape. If it is, would you like it?

[5DIGITS]

The best scenario for the T-III is a properly installed matching melonized TSB set which has the hardening equalized between the two gears.
This reduces concern of either gear having greater or less surface hardening treatment, which can be just as conducive to premature wear.
Regardless, the care provided during the installation of the shaft can determine the longevity of the assembly.
This is witnessed when some stock engines survive excessive miles while others fail prematurely, with or without melonized, cryogenic, or standard treated components.

[shellboy]

i did the " jackson mod " already, but the motor blew a rod and broke the aux shaft in to five pieces!!

[iTurbo]

I've been following/tracking this issue for what seems like forever. I have yet to have a problem with TIII I-shafts or oil pumps. My TIII problems seem to revolve around rocker arm rollers seizing.

Just based on my experience, I think you could install just about any old I-shaft and be just fine. Inspect the shaft and oil pump and be sure the gears are in good condition. Tension the T-belt properly, and look into Jackson's timing belt idler mod if you are really worried. I am not making big HP here, so take that with the grain a grain of salt.

[5DIGITS]

I've been following/tracking this issue for what seems like forever.
I have yet to have a problem with TIII I-shafts or oil pumps.
My TIII problems seem to revolve around rocker arm rollers seizing.

The roller seizure is an issue - have you reduced the spring tension?
Have any lubrication problems been identified?

Just based on my experience, I think you could install just about any old I-shaft and be just fine.
Inspect the shaft and oil pump and be sure the gears are in good condition.
Tension the T-belt properly, and look into Jackson's timing belt idler mod if you are really worried.
I am not making big HP here, so take that with the grain a grain of salt.

There seems to be a misunderstanding that belt tension is directly related to intermediate shaft failure.
The technical service bulletins and related critical services for belt tension were an attempt to improve belt life.
Unfortunately, there are too many dynamic issues in play, for that alone to correct the problem.
For example, minor changes in intake and/or exhaust cam installation angles has a significant impact on the belts resonance frequency.
This is due to changes in load events and how that timing translates into increased and/or decreased belt load oscillations and the RPM in which they occur.

Not until excessively tight belt tension is realized will it have an effect on the front intermediate shaft bearing and likewise not until excessively loose tension will the belt oscillations impact the 'ratcheting' effect on the gears.
Otherwise, a near correct belt tension will have little if any impact on gear failure.

With all this said, your statement of using nearly any shaft is very very true !
When they are properly installed, they will outlast the best gear set that has been poorly aligned.
I cannot emphasize this enough.. Installation and equal rotating loads throughout the pulleys rotation is absolutely critical.

[iTurbo]

The roller seizure is an issue - have you reduced the spring tension?
Have any lubrication problems been identified?

Yes, I have always run the titanium valve spring retainers on my TIIIs. Haven't done anything else to reduce spring tension. I chalk up the roller rocker failures to years of running with the excessive spring tension and poor maintenance. Unfortunately I happened to buy these cars used....I have had three failures. The first was after I bought my red Spirit R/T and finally noticed it was running on 15 valves after pulling the valve covers for the first time. The rocker was ground down to be 'useless' to the point it no longer contacted the camshaft. The second time it was after buying my white Spirit R/T and pulling the valve covers for the first time; same 'fix' as before. The third time it was after pulling the valve covers off the red Spirit R/T to do routine maintenance and check T-belt tension (loosening rocker shaft bolts) and it wiped out a lobe on my S1 cams from Lone Wolf Performance. The roller had seized and had spread metal particles all over the engine and I found bits of the roller needle bearing in the oil pan. The lobe was ground down to near base circle. Good grief!

There seems to be a misunderstanding that belt tension is directly related to intermediate shaft failure.
The technical service bulletins and related critical services for belt tension were an attempt to improve belt life.
Unfortunately, there are too many dynamic issues in play, for that alone to correct the problem.
For example, minor changes in intake and/or exhaust cam installation angles has a significant impact on the belts resonance frequency.
This is due to changes in load events and how that timing translates into increased and/or decreased belt load oscillations.

Not until excessively tight belt tension is realized will it have an effect on the front intermediate shaft bearing and likewise not until excessively loose tension will the belt oscillations impact the 'ratcheting' effect on the gears.
Otherwise, a near correct belt tension will have little if any impact on gear failure.

With all this said, your statement of using nearly any shaft is very very true !
When they are properly installed, they will outlast the best gear set that has been poorly aligned.
I cannot emphasize this enough.. Installation and equal rotating loads throughout the pulleys rotation is absolutely critical.

Thanks for this post!
I have tried to be as diligent as possible when installing TIII timing belts. Perhaps having adjustable cam sprockets is helping more than I thought. It is a bugger to get them timed right, I will say that much.