Good Day, I have a 1987 cat 416 that is slow to engage when shifted into fwrd or rev equally. It has tons of drive power, no slippage, just bout a 5 second pause before it kicks in. Have changed oil and filter, checked and cleaned screen, slight debris but nothing earth shattering. neutralizer functions and suffers the same delay when reengaging. I see I can access the shift valve via under the cab floor, was going to pull it to check for a possible signs of bypassing but figured someone may know how and where to tee in to check pressures prior to tearing it apart to help pinpoint this issue? Thnx
Should have diagnostic ports, access plugs etc. Some might even be marked what they are. trial and error until someone smart steps in. What type of shuttle is it?
Hi you haven't given a serial number so it is very difficult to help below is schematic of a basic transmission oil flow. this is a very simple circuit however the FNR control can be mechanical or electric if it is mechanical have you checked that linkage moves freely and has the correct travel? if it is solenoid FNR have you checked the electrical system for correct voltage? have you checked the voltage at the coils? you said you checked the screen ,did you mean the one under the hex head? Have you checked any system pressures? As stated before we go any further need serial number Mark
It's a 6y2598 transmission, pin is spc05466, yes suction screen is what I checked, mech linkage is tight and travels fully, Am going to check pressures but have no specs At hand.
Hi if after you pressure check the system and the pressures are ok, but sluggish it would be worthwhile to remove the FNR valve and check the orifice for the load piston. a small mount of contamination here a could cause the issue you have.
Anyone find a resolution to this issue? My 1987 426 just started to do the exact same thing toda . So odd, in the morning it shifted quickly between forward/reverse. After lunch and since then it's been a 5 sec delay every shift. I want to fix it, I check the load piston, no luck there. Where do I get the stuff to pressure test?
First off Id check the fluid level and the filter make sure the fluid is clean. those Transmissions and valve bodies have tight tolerances. If the fluid comes out and it's white or creamy and it's been like that for a while you're probably into a valve body or an entire transmission the pumps in the torque converter weren't the best in those models it's generally usually cheaper and more effective to change out the entire unit with a reman assembly if the oil is found to be contaminated and the linkages are adjusted up, because generally if you replace one thing or fix one thing something else will go right after it. But if you want to test the pressures I believe there's a guide right above here in the same thread on how to and you can get the quick connects from any hydraulic shop, you need female quick connects and gauges that will go up to 5000 PSI
Found the problem. A piece of the oil filter pleat actually clogged the through hole on the flow control spool. Just a tiny bit of flow could get through. I dont know why the filter imploded though, any thoughts?
First question would be what brand of filter are you using..? Second would be what brand & viscosity of oil are you using..?
It was a cat filter, I didnt install it. I bought it previously installed. My thought would be the filter was defective from the factory. But either way it either failed or was damaged. I put a napa filter on because I am not waiting for a cat filter to come in. Wix are decent filters. I dont know what oil was in it, slightly cloudy/greenish. I put mobile tran 30 hd in it. Expensive quality lube. The drain plugs were fairly clean, nothing stands out as concerning. I will cut the old filter open soon. Cant find my hack saw.
Mobiltrans HD30 oil ought to work fine in the transmission. I understand not wanting to wait for a filter but I'd get the NAPA one out of there and replaced by a good quality filter as soon as practical. We'll have to agree to disagree about Wix being good filters, I'd class them only just above parts house own brand. Is it possible that the piece of filter you found blocking the bleed hole in the spool could have been hiding in a corner somewhere from a previous change and moved when you were changing the oil recently..?
Do I read this to mean you are not sure what filter failed? Could be previous owner had a filter failure and he installed the Cat filter you took off? Would not surprise me that someone just stuck a filter they had on that "looked the same" and that is why it failed.
Hi, I have an 1986 416 Cat Backhoe with the same issue. Slow to engage into forward or reverse. Some days are better than others. Changed the fluid and filter the other day. Screen was clogged. Worked great after the fluid change quick to engage. Next day worked for several hours fine. After a couple hours forward and reverse became sluggish again until it just wont engage. Let it sit for several hours, restarted and it wont move at all. Coyote, where is the flow control spool located so I can inspect?
Try pulling the screen again and see if it's full of cr@p like last time. It could be you have a clutch on the way out. Load piston is #15 on the illustration below.
Thank you! So #15 on the diagram is the same part Coyote is holding in the picture that was clogged? I'm not sure if I have that same part it's an 86' 416 serial# 5PC00575. I'll check the screen again. I suspect it will be clogged again. No metallic peices that I could see. Thanks for your help.
One and the same. You'll find a small hole in the end of #15 that may be plugged. Be careful disassembling not to damage the gaskets #16 & #18 when you pull it all apart. My worry if the screen has material in it the 2nd time you remove it is a possibility of a clutch failing inside the transmission and the friction material is finding its way to the screen.
Ok thanks Nige. Yes once in gear there is no slippage and plenty of power doesnt seem like it is failing but I don't know much about these backhoes. How big of a job is a clutch replacement?
Ok thanks Nige. Yes once in gear there is no slippage and plenty of power doesnt seem like it is failing but I don't know much about these backhoes. How big of a job is a clutch replacement?
I'd suggest to cover all the other bases before you start worrying about the inside of the transmission.
Number 34 in the diagram was the flow valve that clogged. It comes out when you remove the large cap.
Apologies. I focused on Mark250's post #5 where me mentioned the Load Piston orifice and missed the fact that CLF stated that he found the material in the flow control spool on his machine. Load Control Piston is #15. Flow Control Spool is #34. BOTH the above have orifices in them therefore both could potentially be partially plugged.
Thanks guys! No worries Nige I will check both out when I get a chance tomorrow as well as check the fluid and screen again. I will report back soon. Appreciate the help!
One more thing, did you pull the floor of the backhoe up to access?
Drained the trans fluid again the screen was completely covered with gunky material as you can see...no fluid was able to pass through. Once the material was cleaned off of the screen and the fluid placed back in the backhoe engaged in forward and reverse no problem. It should be noted that previous to pulling the screen this morning I could not engage in forward or reverse even after sitting for several days... Question where is this material coming from? The clutch?
A clutch would be the most likely culprit. What did the oil look like..? Dark and ahad burned smell..? There are actually two clutches, one for forward, the other for reverse. See Mark's post on Page 1.
It was a little dark but still somewhat clear. I had just drained and replaced it last week. Didnt notice any smell but it was'nt warmed up when I drained it. The backhoe had been sitting a few days.
Just out of interest what oil are you using in it..?
I believe a Napa brand SAE 30 hydraulic transmission oil.
Not sure what was in it before this change.
Much as I don't like parts store oil I don't think it would react like that photo, unless it was possibly reacting with the leftovers of whatever was in there before. Does the debris on the screen feel somewhat "gritty", and have you tried waving a magnet over it to see if there is anything metallic in it..?
No, the material is soft not-gritty feel to it. Yah without seeing actual pictures of the clutch assembly it's hard for me to picture where this material is coming from. Not sure if there are any runner components in there breaking apart with age. Very little metal on the magnetic bolts. I also opened the large plate on the opposite side of the screen. I could see all the gears in there. Nothing seemed chewed up.
This is a snip from Marks post on page 1. The clutches are #1 & #2. They are pretty much identical in design to a multiplate clutch on a motorcycle, just bigger in scale and activated hydraulically instead of by a cable.
Very cool! Thanks for the info Nige. I'll post back if I have any more issues.
Well after working for a year or two....I lost forward and reverse while coming down a hill. I drained the fluid and cleaned the main transmission oil screen under the machine. It was full of particles. They felt soft to the touch and black in color. The fluid looks like coffee w/creamer. Yellow/brown. I refilled and it worked for an hour or two until it would not engage into reverse. It however would go forward. I have opened the floor of the machine and removed the shuttle controller/mixer looking for clogged orifices. I have not found any clogs however I did find a broken spring. Which is broken into 3 separate pieces. Could this be causing an issue?
The broken spring is #14 in the diagram. I need to find the part # to see if I can replace.
Most probably what was left of the friction material from the reverse direction clutch.
Yes, that's what I am thinking...what is the best website to view parts diagrams for these machines. I need to find out what part# spring #15 is. Either way it should be replaced. I most likely will drop the transmission and rebuild.
See if the attached is of any assistance.
Thank you. Found the part on the CAT website.
Well unfortunately even with a new unbroken spring and complete clean out of the shuttle controller I still do not have power in reverse. Only forward, which is still strong. When the rear tires are lifted off the ground via the stabilizers, the tires will move in reverse and increase in speed when given acceleration. However I have no reverse power in any gear when tires are planted back on earth. I'm thinking the reverse clutch friction plates are worn down and slipping. Rebuilt tranny units are going for $11k. So next question, if I do drop the transmission and do a rebuild any direction on what internal wearable parts to replace? The web seems to be quite silent on these matters. Thanks!
S/N: 5PC00575 1987 CAT Backhoe
Transmission # 6T-4974
Before I drop the transmission I took the transmission controller back apart to make sure I had everything in correctly. I noticed I have an extra spring below #12 in parts diagram. Spring fits in first then #12. However there is no spring on this diagram and I have no other place to put it. Could this be an error on their part? It's a really long spring, I have springs #13 and #14 so its not those.