Need help interpreting Allison 643 Fluid analysis report

[hemant]

Hello all,

During pre-purchase inspection of 1999 Fleetwood Bounder diesel, I had transmission fluid analysis done. The report is attached and has quite a few yellows and oranges. The recommendation is "use portable filtration system and/or filter change". The report also says that "Particle count is at SIGNIFICANT LEVEL".

The coach as 138k miles. I was wondering what my action on this would be. I am guessing filter change is a must. Do I need fluid flush? What about portable filteration system? Should I just take it in for a transmission service? Anything else that the report implies?

I will really appreciate any help and recommendations?

Regards
Hemant

[n2zon]

Originally Posted by hemant

Hello all,

During pre-purchase inspection of 1999 Fleetwood Bounder diesel, I had transmission fluid analysis done. The report is attached and has quite a few yellows and oranges. The recommendation is "use portable filtration system and/or filter change". The report also says that "Particle count is at SIGNIFICANT LEVEL".

The coach as 138k miles. I was wondering what my action on this would be. I am guessing filter change is a must. Do I need fluid flush? What about portable filteration system? Should I just take it in for a transmission service? Anything else that the report implies?

I will really appreciate any help and recommendations?

Regards
Hemant

Tom Johnson is very friendly. I would ask him for help with the interpretation by sending him a note: tjohnson@jglubricantservices.com

But without any history of the last change, knowing which lubricant it is, and with the findings...I would be tempted to run away from the deal.

[hemant]

Originally Posted by n2zon

Tom Johnson is very friendly. I would ask him for help with the interpretation by sending him a note: tjohnson@jglubricantservices.com

But without any history of the last change, knowing which lubricant it is, and with the findings...I would be tempted to run away from the deal.

Thank you so much n2zon. I emailed Tom with the question.

Is there any particular reading in the report that you find concerning? Or just the fact that there isn’t enough history.

[n2zon]

Originally Posted by hemant

Thank you so much n2zon. I emailed Tom with the question.

Is there any particular reading in the report that you find concerning? Or just the fact that there isn’t enough history.

Tom's an expert and I have had exactly two oil analyses done, one for the engine and one for the transmission. So take this with a large grain of salt.

But without knowing the lubricant used, or how long it's been run, what you have is a random snapshot of oil condition. That snapshot says the oil is "abnormal" (4 on a scale of 1-5 where 5 is the worst rating), and it recommends some remedial actions. You have no idea how long it's been that way, whether any internal damage has been done, or the extent of any damage that might have been done.

I think the recommendations are geared toward owners, not prospective buyers. If you owned the coach, you would want to do what the report suggests, at least. Since you don't own the coach, you have to make a choice between buying it and walking away.

For comparison's sake, my transmission oil report came back with *zero* particles across the board, with 90K miles on the original factory fill of Transyd. It had an overall rating of Severity 1 (which caused momentary panic for me because where I worked, a Sev1 problem was the most urgent!), or "Normal."

[hemant]

Originally Posted by n2zon

Tom's an expert and I have had exactly two oil analyses done, one for the engine and one for the transmission. So take this with a large grain of salt.

But without knowing the lubricant used, or how long it's been run, what you have is a random snapshot of oil condition. That snapshot says the oil is "abnormal" (4 on a scale of 1-5 where 5 is the worst rating), and it recommends some remedial actions. You have no idea how long it's been that way, whether any internal damage has been done, or the extent of any damage that might have been done.

I think the recommendations are geared toward owners, not prospective buyers. If you owned the coach, you would want to do what the report suggests, at least. Since you don't own the coach, you have to make a choice between buying it and walking away.

For comparison's sake, my transmission oil report came back with *zero* particles across the board, with 90K miles on the original factory fill of Transyd. It had an overall rating of Severity 1 (which caused momentary panic for me because where I worked, a Sev1 problem was the most urgent!), or "Normal."

Thank you so much again for the caution and the recommendation to get in touch with Tom. He was really helpful and was able to look at the report and send me his feedback on a Sunday - going as far as to adding one more viscosity test!

His feedback is that the transmission and oil looks good. It is the filter that needs to be changed. I will ask the dealership about this and see if I can find more history on the oil and changes.

Thank you very much again!!! This is really very helpful.

[n2zon]

Originally Posted by hemant

Thank you so much again for the caution and the recommendation to get in touch with Tom. He was really helpful and was able to look at the report and send me his feedback on a Sunday - going as far as to adding one more viscosity test!

His feedback is that the transmission and oil looks good. It is the filter that needs to be changed. I will ask the dealership about this and see if I can find more history on the oil and changes.

Thank you very much again!!! This is really very helpful.

Sure thing. Like I said, Tom's an expert and I am emphatically not. He signed off on the Transyd spec when he worked for Allison. For any oil analysis involving an Allison transmission it is probably very, very hard to find anyone better qualified than he is. Senior engineers who sign off on specs like that one are not exactly a dime a dozen. If he says things are OK, it's extremely likely that he's right.

[vettenuts]

If you haven't bought the unit yet, make the fluid/filter change part of the sale and insist they use Transynd (or same spec) fluid. I suspect your current may be Dextron III, which has been since replaced by Transynd.