I just bought a Clark 55b I was wondering if anyone had any experience with the transmissions/ torque converters this loader seems to be pretty weak once out of first gear. It moves in the other gears but it does not get up to speed as it should in second and third gear. The engine rpm is governed at 2200 rpm right now which I will be turning up to the 2800 rpm the 4-53 Detroit should be at. Any help would be great! Thanks!
I don't know about Clarks, but any of these need the right oil, clean oil, filters & screens to work right -
Thanks for the reply. I ordered a shop/service manual on the loader so I know what's going on with all that and what exactly to check. Second gear in the loader seems to be the strongest yet it even is still weak.
engine stall speed is critical to make the convertor give full power to the trans. Stall speed range 1800-1950 RPM at full throttle and hydraulics engaged at 2250 PSI and oil at 180 Deg F. with trans in high gear and machine locked down, Go down through the rest of the gears, observe the drive shaft between the convertor and transmission with the machine locked down and in gear there should be no movement , if the shaft is turning in any gear, the clutch in that gear is slipping, if it is moving in fwd or reverse in all gears then that clutch is slipping. H Free Idle 2650 RPM.
What is the converter pressure supposed to be. With cold oil we had 175 psi which I think is too low isn't it supposed to be 240 psi with 180-200 degree oil? Thanks for the info though I hadn't thought about locking it down that way and observing the drive line but if the pressures are not right then the clutches would slip right?
That pressure you are reading at the convertor is clutch pressure, the clutch pressure regulating valve is mounted on the convertor, it looks like a plumbing fitting. there are two versions that are the same outside but have different pressures depending on what machine it is on, the 55B should be 240 - 280 the other version is 180-220. If some one bought a used one it could be the wrong pressure setting. There is no adjustment just different springs internally. If you have the wrong one you can get a spring set or replace the whole thing. minnpar.com is handling clark parts also you can get maunals there just down load what you need.
I went to Lakewood High School grad. 1956.
Okay I'll check it out and see what I have for a regulator. It does look to have been replaced.... Recently
What trans is in your loader? I have a 45C with the 18000 series, My 4-53 was only turning 2400 rpm's, machine felt like it slipped all the time, got the rpm's up to almost 2700 what a difference! but it still cant compare to my Dresser 515b
I have a 28000 series trans Ill check the rpms and get them set to the proper spec of 2650 as the previous poster said. I know a 4-53 is good for up to 2800 but the converter ect may not be good for that high.
Still Having issues with this transmission. It does operate better now that I changed the oil and installed a filter(it was missing lol) trans was about 2 gallons low as well. Now however I am having oil leak out of the breather on the torque converter????? Is the converter possibly leaking and spraying oil up at the breather or maybe the drain is partially plugged? Not a major leak but its enough to make a puddle while is sits and idles for 5-10 minutes.
Non of the clutches are slipping though! locked the machine down and I get no driveline movement in any gears when engaged. only spins when the wheels turn.
Full serial number of machine would help in obtaining the correct pressures and engine speed specs.
here is the serial number 416C-968-CAC
Clutch pressure 240-280 psi Convertor "In" @2000 RPM 40-75 psi Convertor "Out" @2000RPM 30-55 psi Cooler "In" @2000 RPM 20-44 psi Cooler "Out" @2000RPM 20-25 psi Convertor leakage 2 GPM Max@2000 RPM No load. Engine Stall 1800-1950 RPM 3rd gear and hydraulics over relief. Do not stall for more than 30 seconds. Engine HFI 2650 RPM Main hydraulic relief pressure 2250 psi All tests should be carried out at normal operating temperature. (180 deg F ). Regards
Thank you Neil! Very good information! I am going to assume with oil coming out of my breather my converter is probably leaking excessively or the drain line is "plugged" or restricted.
The "breather" on the convertor is actually a check valve to let air in so you can't get a vaccuum in the system but should block oil coming out. there is a plastic check valve inside, and they are prone to come apart over time and start letting oil come out.
Oh very good thank you
checked the pressure today on for clutch pressures all gears forward and reverse are reading 162-165psi.... thats a bit far off of what it should be 240-280psi... going to order the proper springs and try that to see if this corrects it. at least I know that the transmission is likely good as all the clutch pressures are dead on together however it is low.
Hello!! You can measure the converter leakage by taking the drain to a bucket for 1 min and measuring the amount of oil. If it is more than 2 galons in 1 minute at 2000rpm then you have an issue. If the return line to the transmission is not clogged, then you probably have a worn breather. If you replace it it will all be ok. Also, if you have a slipping converter, you will get high stall speed (more than 1950 rpm), so it is also a way of determining the status of your converter. Regards
For drain are you talking about the main drain from the bottom of the converter to the transmission? Because doesn't the oil from the cooler return into the converter or is there another drain? This unit seems to have a lack of power when you are running it,it will somewhat bog the engine down in 2nd and 3rd gear on flat ground no load 3rd gear is very sluggish and it won't pick up any speed only down a hill and in 1st gear it doesn't have much pushing power. I read a deal in my manual last night that said units with serial number 416c 101 fsc and up have 150 to 175 psi clutch pressure for modulated transmissions but my serial number is 416c 985 cac does this apply to mine or no?
Yes, I mean from the bottom of the converter to the transmission. The oil from the cooler is returned to the transmission through another port in order to cool and lubricate bearings etc. You have to stall the engine in all the gears in order to identify where the problem is. When you stall it as some other guys described above, you can easily see if the transmission is slipping by watching the propeller shaft (converter to transmission). If the wheels are not moving and this shaft is moving, then you have a slippage in the transmission. You can test all your gears this way. In the slipping gear the shaft will rotate. If it is not rotating in any forward or reverse gear, then you have to troubleshoot the converter and the engine. Regarding the pressure, if you give me the model of the transmission from its nameplate I can tell you if you need 150-175psi or 240-280psi.
Okay I will get you the info off the tag thanks for the help
If you have a modulated (soft shift) transmission, the early ones had clutch discs coated in organic material, which didn't work out to well so a change was made to bronze clutch discs. If the trans was repaired and the bronze discs were put in the clutch pressure had to be raised from 180/220 to 240/280. Could be that the trans was updated and the clutch pressure regulator valve was not or it was replaced at some later time with the wrong regulator valve. That all said, if there is no sign of clutch slipping by observing the drive shaft to the trans from the convertor there is probably a low engine stall speed or a massive amount of internal leakage inside the convertor or foaming oil due to the charge pump sucking air from some where.
Trans model is r28420-500 serial number 248261T it looks like the charge pump is new and the regulator valve has been replaced I cleaned the screen and found hardly ant thing and replaced the drain lines engine is rebuilt I just did that
Is there a way to tell if the Trans is a soft shift transmission from driving it around it shifts pretty hard as it grabs from forward and reverse hooks up good and you know it shifted.
Hello!! You should have 240-280 psi clutch pressure according to my files. If you cannot find new springs for the valve you can try installing washers in the back of the spring to increase the pressure. Regarding soft shift, I guess you are referring to modulation. The transmission should be modulated. You can see it by the extra section on the transmission control valve, where the levers end up to. In non modulated transmissions there is only one section. On modulated transmissions there is an extra section between the control valve and the transmission housing. If changing from F to R is harsh, you should check some springs located in this etra section. Maybe you can do it without taking it out, since these springs are behind plugs in this middle section, 2 under each plug on top and 1 on each side.
It did shift pretty firm I'll check for this extra section could it possibly be loosing pressure in one of those sections and also causing a hard shift and low pressure?
Yes, there is a slight possibility for this to be happening.
Okay thanks again for the indo I'll post an update tonight
Pulled apart the regulator valve on the torque converter to find that it only has one spring in it. Aren't these supposed to have two springs???
Should be two springs for 240/280 valve, Outer, Clark PN 224369, Inner 224368
Got them both coming will be here tomorrow I am hoping this is the problem I would assume it has a lot to do with it lol
Okay so got the springs and new gasket and o ring put everything back together fired it up and bam 275 psi.... but it still seems really weak unless the oil gets hot which is pretty normAL for most loaders and things with torque converters right? The problem now seems that I cannot get the oil to operating temp of 180 . Checked for slipping in the transmission in all gears forward and reverse and no slippage holds like a brick. Why would the oil not want to heat up I even checked it with my infered gun and it only got up to 123.5 degrees f after stalling it in 3rd gear I got it to 160 and it ran very good but cooled down very fast which is a good thing. Just seems with 165 degret coolant it should warm up a bit but I suppose at the bottom of the radiator it could be around 120 to 140 on the coolant just seems that it takes waayyyy to long to get hot and not just hot but warm. Going to check all pressures tomorrow and also do a converter leak test to see what's going on but main clutch pressure is 275psi now and holds that in all gears forward and reverse
So check everything all pressures are within spec even did a converter leak test which is pretry difficult to get perfect but I got 2.25 gpm on that which technically is over spec but again it's about impossible to do dead acuretly. I happen to think maybe my engine is a little weak... otherwise I am not sure what else it could be.
oldsabee, when you do the stall test you put it in high gear forward or reverse with parking brake set floor it... then roll the bucket back and hold the lever and read rpm correct? or do you just put it in gear and do it. in gear only not doing the hydraulics i get 1937 rpm
Ryan151 - sorry to hijack your post, but quick question. Where did you find a shop/service manual? I have been having no luck finding one. Thanks!!
I cannot remember where I got it from but I know Minnpar told me you might call them and ask. However if you've got a 55b I have that manual and could get you a copy for reasonable. I know I payed 200 something bucks for it
Inquiring minds want to know. How did you make out on this unit? We just pulled the V378 out of our 55B and put in a 453. Had the same fun with the engine RPM but have it corrected. Unit was a beast before but now 1st seems lower, 2nd is like first was and 3rd is like 2nd. Doing pressure tests tomorrow. Was looking for a manual on the tranny and converter for service. We have a R28320 Tranny SN 007615 and torque C272-92 SN 730 7J in our unit. Good input on the valve on the side. Was wondering what we were getting into. Oh and on the oil temp issue.....It was December in Colorado.....I saw that the 453 runs cooler than the V378 did all the way around. We use a bypass valve on the radiator cooler in the winter on ours. Set of three way valves in the lines with a bypass line.
Hello there!! Your Cummins engine should have a HFI (Hi Free Idle) of 2.650rpm and a full stall speed of 1700-1900 rpm. The replacement engine you used should have similar characteristics, else the machine will never be the same again. So, first of all measure the HFI rpm of the 453 engine. From the symptom you describe I think that you will not have the stated rpm. Try to fix this and things will be better, if not the same. Also, I see in the parts book (which you can download from Minnpar) that the converter gears and impeller etc and some transmission gears are different with Cummins engine and with Detroit engine installed. This is usually done due to the different power curves of the engines and the different HFI rpm. Anyway, if you manage to fix the rpm of the 453 your problem will be more or less fixed. Check it out and let us know.
mourafetis, Thanks for the info. The Cummins really made it talk but only at higher RPM's We had constant problems with it though. The previous owner had replaced the head gaskets being mis informed about oil leaking into the water being head gaskets. When we got it we went thru the oil cooler and checked everything ( we thought ) and it was better for a while. It ended up not being the brass tube section leaking but the actual casting that the oil ran thru. We removed the oil cooler and made a block off plate and installed an external filter and pretty much had it licked. However there was still oil sludge in one of the head's even after aggressive hot water and caustic flushing and one of the heads cracked over a very cold section of winter. We fired it up in the spring and in short order it took out a piston and sleeve because it cracked thru the water jacket and the fuel section. Classic vapor explosion. We replaced the piston and sleeve and checked the bearings. They were still in spec but had planned on a full rebuild over the winter. We replaced all of the injectors because we noticed that they were not giving a good pattern and rebuild was as expensive as new. Once the new ones were in it really worked well. Ran like a champ for about two months better than ever before and then it spun two bearings. We were going to do the rebuild and then decided to put the 453 that we took out of an excavator and had saved for a rainy day project into the machine. 453 was rpm limited at 1950-2150 RPM. Pulled the stop rings out of the governor and set her to run 2700-2800 RPM. Checked the converter and pump pressures after finding out correct test ports and have 15-20 on converter just off Idle and 35-45 at 2000 RPM. Pump was running about 230-240 at 2000 RPM. First gear is now stronger than it was and so is second but third is very weak. Hot or cold ran the same and pressures stayed within 10 lbs on the pump and 5 on the convertor. Just got done pulling the regulator valve assembly off. Was surprised about how crude the machining was on the convertor ball and seat. They are cleaned up and lapped. ( spacer under the spring to see if we bump up the convertor pressure ) Pulled the main spring assembly apart and found two springs and lots of crud. Was going to just put a spacer under the springs but I cheated and drilled out two 7/8 nuts and made a 3/4" line up tube and dropped it into the valve assembly. Welded those and a third nut with threads on the top end. Made up a 7/8 all thread adjuster screw with a just under 3/4 drop and threaded it in. Instant adjustable pressure. Back onto the machine tomorrow to try it out.
Sorry for a late reply... But my 55b is still running awesome! I'd keep getting stuff cleaned up check the pressure for the clutchs especially third sounds like. To check it out a 0 to 400psi gauge in that port on the bottom left side of the ref valve do this test with oil at 180 or above temp. Clutch pressure should stay close to starting pressure when in neutural. I had 275psi never less than 270 in all gears forward or reverse . if all this she is good its a Likely an engine power issue. I thought I had a bad third gear as well but it turned out my rack was set just slightly off and not giving full fuel. Let me know if you need info from the manuals I have them on the tc and trans and 453. Also could do a slip clutch check by setting brakes or stuffing bucket in a pile. And put her in third and forward and punch it. Have assistant watch driveline between engine and trans and if it spins without the wheels moving you got problems....send me pm if you need I'll help all I can
Ryan or otherwise. Is there a port or ports on the transmission to read the pressure in each gear or just the lower port on the regulator valve? Got valve back on and now have 20 lb at idle on convertor and 50-60 psi at 2000 RPM and 285-300 on the pump at 2000RPM in 1st gear with brakes locked up and no shaft slippage. The adjustment screw worked great for relief setting. Haven't taken it out and run it in the pit yet because I had other stuff to work on today and my brother was going to a Softball tournament for his daughter.
Let me post some pics
here is a picture of where to check the relief valve pressure which is the clutch pressure for the transmission do this with oil at 180 deg f or higher. at idle in all gears forward and reverse should read 275psi but there is a revision in my shop manual that shows a lower pressure for modulated trannys:
Ryan, Thanks for the picts. I'd drop you a few bucks for a copy of the service manuals you have. If you have them in digital You could send them thru sendanywhere.com to [email protected] and let me know what you need for them. If paper back only let me know what copy costs are and shipping and what you need. I've done full pressure tests and have 45-70 psi on the converter and 270-300 on the main pressure hot in 1,2 and 3 is about 270 tops and very weak. 1st and 2nd have plenty of power but machine moves slower than it did. SHOUT OUT, I read that the detroits took a different converter than the Cummins motors. Anyone have any input or specs on this. Looks like a tranny tear down for the fall and want to get converter figured out before then. Love this with the 453 for power, now for new tires as 1st spins em quicky and second is breaking them part of the time. Ryan, I'll give you a call later this week when timing works out hopefully but let me know on manuals or call me at 814-881-4093 when you are free. I'm up way before you get up and don't get to bed till after 1 most days. Thanks again Jerre
I'm sure we can work something out. Give me a call and well talk
Ryan, thanks for the quick work on the injectors. Those and the tach installed and I can finish trouble shooting. Sounds like you said it's the same progress you had on yours. Good luck in the topsoil. Jerre
no worries Jerre they shipped out this morning(friday morning) call me if you have anymore trouble.