TC88 After the tensioners self distruct, now what ?
#1
TC88 After the tensioners self distruct, now what ?
My first twin cam. I knew enough to look for the correct push rod tubes that are used for the adjustable push rods. That let me know someone had been in the cam chest to change out the tensioners. Didn't notice the low oil pressure. There were some unexpected hidden issues that had to get sorted out that distracted me for a bit. Those are cleared out and I went for a ride. Oil pressure was max 22 psi. Opened the cam chest again to inspect the oil pump. Yep, it was not aligned correctly when the tensioners were changed out. But that's not all. There is plenty of evidence that some steel went through the pump to help it on its way to the trash can. So the previous tensioners probably took out the cam chains as well. The lifter bores look mirror perfect. which is encouraging, but the crankshaft, where it passes through the cam plate brass bush, looks to be slightly scored, the gearotors are scored half to death as is one side of the pump, both scavage and pressure sections. Yeah, I am going to mic the shaft and the cam plate brass bush for wear. The brass bush looks good. Perhaps it has been replaced already. I know the oil was changed a few days before I bought it, so an inspection of the magnetic plug probably will show nothing. I'm seeing a very small trace of aluminum, almost a powder fine trace, in the cam chest. I'll pull out the oil pressure piston and clean out the relief passage to be sure its not sticking. Any tips from folks who have been in this situation ? I'd love to hear from someone that can say, " been there, done that. Got 15K on the clock since then... ". I won't say much about the previous owner except to suggest that it takes more than a hammer and a credit card to be a mechanic.
#2
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It runs, it has good oil pressure...ride it. I have seen a few TC88's run until the tensioners have exploded and then been run some more (a lot more in some cases) before they got pulled apart.
I would change the oil again, cut the filter open and if it's all good and it has good oil pressure then I would keep riding it with not much more than a new or second-hand cam plate and pump internals.
I had an Ironhead once, ran it for years with no issues until one day I took it apart out of curiosity, the oil pump looked like it had been eating gravel and scrap metal.....8 years later, the guy who owns it now is still running that same oil pump.
I would change the oil again, cut the filter open and if it's all good and it has good oil pressure then I would keep riding it with not much more than a new or second-hand cam plate and pump internals.
I had an Ironhead once, ran it for years with no issues until one day I took it apart out of curiosity, the oil pump looked like it had been eating gravel and scrap metal.....8 years later, the guy who owns it now is still running that same oil pump.
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#7
Just a few thoughts on the OP.
Paragraphs would make it easier to read and follow; I had to read it several times to put together a reply. Make, model and mileage would be good to know as well as any modification details; pictures always help.
So, what I gather from the OP the tensioners were replaced by the previous owner but not the oil pump; strikes me as unusual but certainly could be the case.
There were some "unexpected issues" but they have been addressed. Information that should have been provided by the OP for the bigger picture.
Max oil pressure is 22psi which the OP attributes to mis-aligned oil pump but no mention of oil pressure with new pump. Assumed new pump because the old pump found its way to the "trash can". Would like to know oil pressure after new pump, properly aligned was installed; pretty important piece of information.
The steel material that would have been eaten by the oil pump could be the mild steel carriers holding the tensioners or the inner cam bearings. If either was the case, there could be more swarf circulating in the oil and/or sitting at the bottom of the crank case. I doubt that the chains were damaged.
Pictures would help but scoring of the crank is probably a non-issue; however, it would be worth checking crank runout while the cam chest was open; it would be an oversight not to check. I suspect the brass bushing in the cam plate is fine; I don't think I know anyone that has had to replace one but certainly possible. No mention of scoring the cam plate at the interface between the pump and the cam plate. If the gerotors are as bad as the OP describes, that surface should be scored;maybe not beyond repair but should show signs of material passing through that shouldn't have.
The OP should also check the inner cam bearings to see if INA or full compliment; if INA, the OP should replace them with the full compliment pieces.
Those are a few of my thoughts after having "been there, done that".
Paragraphs would make it easier to read and follow; I had to read it several times to put together a reply. Make, model and mileage would be good to know as well as any modification details; pictures always help.
So, what I gather from the OP the tensioners were replaced by the previous owner but not the oil pump; strikes me as unusual but certainly could be the case.
There were some "unexpected issues" but they have been addressed. Information that should have been provided by the OP for the bigger picture.
Max oil pressure is 22psi which the OP attributes to mis-aligned oil pump but no mention of oil pressure with new pump. Assumed new pump because the old pump found its way to the "trash can". Would like to know oil pressure after new pump, properly aligned was installed; pretty important piece of information.
The steel material that would have been eaten by the oil pump could be the mild steel carriers holding the tensioners or the inner cam bearings. If either was the case, there could be more swarf circulating in the oil and/or sitting at the bottom of the crank case. I doubt that the chains were damaged.
Pictures would help but scoring of the crank is probably a non-issue; however, it would be worth checking crank runout while the cam chest was open; it would be an oversight not to check. I suspect the brass bushing in the cam plate is fine; I don't think I know anyone that has had to replace one but certainly possible. No mention of scoring the cam plate at the interface between the pump and the cam plate. If the gerotors are as bad as the OP describes, that surface should be scored;maybe not beyond repair but should show signs of material passing through that shouldn't have.
The OP should also check the inner cam bearings to see if INA or full compliment; if INA, the OP should replace them with the full compliment pieces.
Those are a few of my thoughts after having "been there, done that".
Last edited by djl; 05-22-2024 at 06:30 PM.
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#8
it not us being mean, Could just move on, instead of trying to help the guy.
Trying to guess what is going on. My guess is oil pressure low so he took it apart. But has not installed new oil pump yet, and is trying to decide what to do.
Not saying you need to, but is not as hard as you think to pull an engine and split case, as you think. Thoough id consider flushing with kerosene. I'd do some searches on the forum from 20 years ago, and see how far people went.
If you pull the top end off, you could get a little bit of look, and operate rods to see how they feel. But again I would look at some old threads. I discovered bad crank bearing by operating by hand, they would not fall easy.
#9
#10
I just noticed that Vickersguy posted on 5/13, "Retrofit 2007 Cam Hydraulic Plate into a 2004 Twn Cam", so I assume he is working on a 2004 model, which one he didn't say in that post. According to that post he is dealing with "low oil pressure" and "shot lifters" but at that point, I don't believe he had opened the cam chest.
@Vickersguy For future reference, you will get better information if you start a thread and keep it going, even if the subject drifts a bit from the orignal title. This thread makes no mention of converting to a hydraulic tensioner set up and you mention that you are "doing the cam plate bearings, inner cam bearings, lifters and oil pump; all information that was not included in this thread. You might want to update this thread so everyone can see the bigger picture and provide better replies. Keep everything in one place. JMHO.
@Vickersguy For future reference, you will get better information if you start a thread and keep it going, even if the subject drifts a bit from the orignal title. This thread makes no mention of converting to a hydraulic tensioner set up and you mention that you are "doing the cam plate bearings, inner cam bearings, lifters and oil pump; all information that was not included in this thread. You might want to update this thread so everyone can see the bigger picture and provide better replies. Keep everything in one place. JMHO.