d 8n

[Cmark]

Can someone here who has actually rebuilt a Cat torque converter/divider please explain how it is actually physically possible to assemble one incorrectly? They are possibly the easiest powertrain component to build and are basically just a stack-up of round things and thrust bearings. From memory, the only thing to easily get wrong is the sprag clutch and this machine doesn't have one.
The OP stated that his outlet pressure and lube pressure are within spec, so that in my estimation eliminates the sealing rings as a source of trouble.
As far as I'm concerned, an incorrectly built TQ will either lock up on the assembly bench or make metal within seconds of starting. I'm genuinely curious to hear other opinions on this.
Back to Nige's cooler theory.

 

[DoyleX]

Can someone here who has actually rebuilt a Cat torque converter/divider please explain how it is actually physically possible to assemble one incorrectly? They are possibly the easiest powertrain component to build and are basically just a stack-up of round things and thrust bearings. From memory, the only thing to easily get wrong is the sprag clutch and this machine doesn't have one.
The OP stated that his outlet pressure and lube pressure are within spec, so that in my estimation eliminates the sealing rings as a source of trouble.
As far as I'm concerned, an incorrectly built TQ will either lock up on the assembly bench or make metal within seconds of starting. I'm genuinely curious to hear other opinions on this.
Back to Nige's cooler theory.

Been down this road with aftermarket parts. Didnt want to spend the 2k for the cat rear hub and mainshaft, it leaked internally like crazy after it warmed up. Lifting the hub out the ears broke off and upon inspection found that the metal was extremely soft where the sealing rings grooved the run surface in a short amount of time. The hub was also machined out of square resulting in a minute wobble.

 

[StanRUS]

If the seal carrier grooves are roughed up from prior usage with gritty oil or a after market seal carrier is used that has 'non-OEM surface finish and material hardness' the seals will wear out quickly and cause flooding. That won't show up by checking outlet or lube pressures. Two bushings to install to spec'd depth. Oven heating aluminum hub to 300deg F to install parts and freezing bearing race cups. Basically simple to build torque dividers.

657 torque converter support carrier bearing 1T645, finished tolerance after machining 4.5045" +/- 0.0005". A grin to install, roll-burnish into the carrier's groove and finish machine to spec'd tolerance; Cat does not leave much extra material for finish machining.

Timken bearings, they're not all the same and rated by class for run out tolerances and mounting surface tolerances.

I won't touch non-OEM parts for trans or torque dividers including oil-coolers. Simple math; if the parts cause problems I have to eat the labor and parts' cost to replace with genuine etc. Plus pi$$ed off customers.

Non OEM oil coolers. Bigger tubes but fewer to reduce manufacturing costs. You end up with less surface area to transfer heat out the bundle into the jack coolant system.

 

[379Pete]

Can someone here who has actually rebuilt a Cat torque converter/divider please explain how it is actually physically possible to assemble one incorrectly? They are possibly the easiest powertrain component to build and are basically just a stack-up of round things and thrust bearings. From memory, the only thing to easily get wrong is the sprag clutch and this machine doesn't have one.
The OP stated that his outlet pressure and lube pressure are within spec, so that in my estimation eliminates the sealing rings as a source of trouble.
As far as I'm concerned, an incorrectly built TQ will either lock up on the assembly bench or make metal within seconds of starting. I'm genuinely curious to hear other opinions on this.
Back to Nige's cooler theory.

What I’m talking about is the running clearances between the wheels and stator. If the bearings are worn, the impeller/turbine will rub and wear against each other and the stator. If the builder re uses the wheels with new bearings the clearances will be excessive. THIS WONT CAUSE LEAKAGE TO THE CASE/ SCAVENGE PUMP. The Hot oil will go to the cooler and lube circuit but can eventually overwhelm the cooling system. Cat gives a procedure to measure these clearances in the assembly manual. You use steel balls and a dial indicator. The wheels need to run very close to each other to be efficient.

 

[Mobiltech]

The problem I’ve seen with poorly built jobber parts in a torque is that the tolerances between the impeller stator and turbine are not right. The oil still goes out through the outlet relief with no internal leakage but the efficiency of the converter is lost. The converter is a fluid coupler and high clearance makes the coupler slip. Much like a water pump with an eroded backing plate. This slippage generates more heat.
Also on the d8n when they first went into production we had complaints of them running pretty warm on trans temps. They found the coolers were undersized for the machine and later machines and d8r came with a larger trans cooler.

 

[Nige]

At the point where we are right now my money would be on a less-than-perfect rebuild of the torque converter.

 

[StanRUS]

Cat gives a procedure to measure these clearances in the assembly manual. You use steel balls and a dial indicator. The wheels need to run very close to each other to be efficient.

Later torque-divider equipped machines' service manuals no longer show or mention the procedure using steel balls and dial indicator to measure and check Stator-Turbine / Stator-Impeller clearances / *running clearances.

Current procedure; use inside micrometer and measure across the diameters @ two points / 90 degrees spacing and compare to service manual's specifications chart. Minimum / Maximum diameter as specified / *Running Clearances = 1/2 measured diameter.

T/C problem? IMO, most probable.

 

[burns]

if we are thinking the t/c wouldnt my stall specs be wrong creating slip and generating more heat, does anyone know what t/c temp should be generated from inlet to outlet side, i know it depends on conditions but there should be some general temp
obviously queenslander youve had issues with tillys

 

[379Pete]

if we are thinking the t/c wouldnt my stall specs be wrong creating slip and generating more heat, does anyone know what t/c temp should be generated from inlet to outlet side, i know it depends on conditions but there should be some general temp
obviously queenslander youve had issues with tillys

Tough call, could have low engine power and weak converter combining to stall speed in spec! As for temperature readings, think about the latent heat of boiling water. Once water hits 100C, no matter how much you turn up the fire, the water will never get hotter than 100C. The cooling system is absorbing the heat, and your operator stops the machine before it redlines. Probably the only sure fire way to confirm a bad T/C is disassemble and measure. The fact it takes so long to cool off tells me it’s probably the power train. That whole rear housing where the ripper mounts is probably 200F by days end.

 

[Mark250]

Hi, some questions please
Has the engine oil cooler been looked at, as it is series with the transmission oil cooler it will effect cooling ability
Has the correct radiator been fitted. if it is the folded core type with a/con it should have 12 cores.no air con fitted it will have 8 cores plus there are a number of conversions available as well check out SEBD1963
Also if the coolers are clear lower the T/C outlet pressure to low end of spec

 

[burns]

ambient air temp dropped quite a lot today it was 30 deg c the operator told me that the engine did not get above 90deg but the transmisson got to 120, he let it cool at high idle and it took a good 15mins to get the trans down to 100deg. this there fore seems the transmission is thee one generating the heat but i think that the cooler should cool system down a lot more, correct me if im wrong but i think i should look into getting a new cooler

 

[Nige]

A new cooler would certainly be cheaper than digging into the converter again, that’s for sure. Whether it fixes the problem or not remains to be seen.

 

[379Pete]

ambient air temp dropped quite a lot today it was 30 deg c the operator told me that the engine did not get above 90deg but the transmisson got to 120, he let it cool at high idle and it took a good 15mins to get the trans down to 100deg. this there fore seems the transmission is thee one generating the heat but i think that the cooler should cool system down a lot more, correct me if im wrong but i think i should look into getting a new cooler

I really think cooler is doing its job if the coolant temp redlines at the same time the transmission temp redlines and it cold off so slowly. But keep in mind that “we all” are giving free, long distance advice.

 

[Mobiltech]

When they are running it to cool down make sure its revved up a bit like 1200 rpm. That increases cooler flow.

 

[Nige]

When they are running it to cool down make sure its revved up a bit like 1200 rpm. That increases cooler flow.

By the sounds of post #93 above they are running it a High Idle in neutral in an attempt to cool the power train, unless I'm misunderstanding.

 

[StanRUS]

@ burns
Consider Re-checking T/C outlet psi @ high idle, 3rd gear @ stall now with 30W trans oil.
Ref: your reply #34 T/C out 55psi, high idle, 3rd gear @ stall with 50W trans oil.

R&I Trans oil cooler: Check current oil cooler tubes for sediment, crap by using a rod pushed threw each tube. Good window as to the coolant system cleanliness.

 

[Mobiltech]

By the sounds of post #93 above they are running it a High Idle in neutral in an attempt to cool the power train, unless I'm misunderstanding.

Sorry I missed that. Most people will let it sit at idle so I thought I’d mention it.

 

[burns]

yes operator is having machine running at 1500 when cooling down, that was my next step was to check pressures with 30w in it now. when i had the cooler removed i did rod all coolant lines, the operator did tell me that origionally before i was involved it did have a green coolant in it, but he put a flush threw it,
when i changed t/c a month ago i had those tubes off and inspected them, i also checked trans screen when i c/o oil to 30w

 

[Bluox]

What exactly is the tractor doing? Dozing, up hill down hill ect. ?plowing?
Bob

 

[StanRUS]

Bob, last week dozing loose dirt with 40C ambient temp

@burns,
Check trans-lube pressure also to have a reference point.
T/C outlet valve: If your pressure is lower with 30W use 5M9623 spacers and raiser the pressure to 65-70psi. 1ea spacer increases psi 16.5kPa (2.4psi) Spacer thickness 0.90mm (0.035")