David Brown 990 selectamatic clutch replacement #38

[@johnpalmer9774]

I’m serious, I could not do this without your videos. A million thanks to you for these very very detailed and informative videos.

[@manfromthemist1958]

Hi John, many thanks for the kind words it's great to receive such positive feed back about the channel, however I would like everyone out there to know none of it would be worth it without the viewers, yes the tractor would get done as so many do without anyone knowing and the only time others get to see them is at shows or rallies and in the long dark evenings of winter that not going to happen, I know when I watch other providers video's it certainly inspires me to get out there and do more to my tractor. The only regret I have is that I didin't start the series when I started the tractor and so much was missed, nevermind there will be another after this. many thanks please keep enjoying Barry

[@kensimpson7441]

Well done Barry, great progress, great vid, you can't beat a good rant!!

[@manfromthemist1958]

I love a good rant, I'm thinking of starting a new channel that only contains rants and steam letting, probably get sued! thanks Ken Barry

[@larrypayne4193]

Hello Barry: This is a long read ... sorry! A review of the Hydraulic Failure on my DB 990 Selectamatic. Your Videos, support and handholding has been invaluable as was Shane's (Path Of Discovery). The tractor lost all hydraulics while operating an eight foot bush hog. Eventually I had to pull the PTO housing and immediately found the Intermediate Hydraulic Pump drive gear shaft had came unscrewed from the Casting and was just laying there in the bottom of the Casting. The Root Cause of why this happen is a mystery. This Intermediate gear turns counter clockwise - the original engineering should have called for a left hand thread on that shaft. I found that the inside race of the bearing was doing some amount of turning on the shaft which resulted in about .002 wear on the shaft. Your advice of three point dimpling the shaft in five equally spaced locations around the shaft worked great when I installed the new bearing. I was tempted to use Red Loctite on the threads of the shaft but for the benefit of the next mechanic that works on this PTO I used Blue - I might well be the next mechanic! :) I have a worry of how tight I was able to get the shaft - the designer's could have provided a hex head on that shaft; hindsight being 20/20 I should have sacrificed an impact socket and welded two parallel pieces of Key stock on to it. In the process of removing the the PTO the Hydraulic Pump Mounting Plate gasket was disturbed, so I pulled the pump and plate, and installed new gaskets. I did increase the size of the Pump Discharge "0" Ring to 16mm ID X 3mm CS as Shane and Barry had recommended, but it took a bit coaxing to get the Pump on over the larger "O" ring. I was surprised as to how clean the internals of the old tractor was, but I changed the oil and the filter anyway. Other than a new bearing, gaskets, "O" rings, oil (6 gallons) and filter I also purchased a Load Leveler (it's a must have if you are working by yourself) I already had an Engine Puller. I ended up purchasing an Endoscope - without it I would likely still be trying to get the Hydraulic Pump Gear to align with the Intermediate Gear. I did mark the position of the PTO Shaft but lost that mark. The other issue that this tractor was having was the Secondary PTO Clutch was not fully releasing. The last time this PTO was used was in the spring of 2024 and it had been giving issues for a while. At the time of the Hydraulic failure it became impossible to shift the the PTO Gear Box with the engine running. So I was fully prepared to pull the Hood and Fuel Tank and using Barry's Video adjust the Clutch to .070". It went unnoticed by me that the Clutch pedal was not actually going all the way to the floor when attempting to shift the PTO Transmission. With the Tractor's Hydraulics working again I wanted to test the PTO and that's when I noticed that the Clutch Pedal did indeed go all the way to floor this time and the PTO Gear Shift could be operated as it is supposed to. To my knowledge nothing I did in the repair of the Hydraulics had anything to do with the Secondary PTO Clutch - another mystery! I have since put about 5 hours on the tractor's PTO and all is working well - I'll take it!

[@manfromthemist1958]

Well done Larry, pleased to hear all is bck together and working well. many thanks Barry

[@larrypayne4193]

Hello Barry: I hope you received the email pertaining to my PTO/Hydraulics problem along with the pictures. It was somewhat of a wordy message.. Sorry about that. Eventually I will get the PTO & Hydraulic repaired then on to the next issue. Which is the PTO Clutch not fully releasing. I have watched your great video on adjusting the Clutch to .070" a couple of times. I want to confirm that this adjustment can be done through the square access hole in the top of the casting? On my 990 that hole has a vented cover which I find strange that the cover is vented. The hood and fuel tank will have to be removed in order to access the and work through hole in the casting. The part of the Clutch for the Transmission seems to be functioning normally but the PTO Clutch doesn't fully disengage. Thanks again for all the work and effort that you have put in making these video's.

[@manfromthemist1958]

Hi Larry, yes thats right the clutch can be adjusted through the access panel, mine is vented to, and yes you need to remove the tank and hood. I suppose you could do it with the hood on but it will be an awfull fiddle. good luck Barry

[@MusicandMachines]

I’ve been searching all over for that little inspection hole in my 990’s clutch housing, but I don’t see it! Were there different housings made? Also, my 990 has the clutch pedals coming up from the bottom and none of the manuals show an adjustment procedure for that style.

[@manfromthemist1958]

Hi the inspection hole is behind the steering column under the fuel tank, Not sure about the different housings or your pedals, what year was your 990 made? many thanks Barry

[@MusicandMachines]

@@manfromthemist1958 , my 990 is a 1976. Also the badge says it’s a 990/1 as the model. Any significance to the “/1”?

[@manfromthemist1958]

could you make a shorts video of the tractor, manufacturer plate, serial number on the front chassis and pedal arrangements, post it on your channel and I'll get some of my viewers who know a great deal more than I do to take a look and hopefully come up with some answers fingers crossed Barry

[@tonyhargreaves5009]

Hi Barry. Would you (or anyone else) know if the 770 is the same procedure for clutch adjustment as the 990 ?

[@manfromthemist1958]

Hi Tony,, many thanks for getting touch, I'm sorry my knowledge is limited to 990's however some of my viewer's may know, also have you tried the David Brown Tractors page on facebook, someone there will definately be able to help as I think it's about 24K strong. Best of luck many thanks Barry

[@manfromthemist1958]

Hi Tony, drop me an email and I'll send over a clutch manual I've found

[@oskarlago1368]

Hello Barry! Great videos I’be just replaced the dual clutch on my 995 from 1973! There is a big gap between the pressure plate and the tread bearing! When I adjust the freeplay it Will connect but it still feels ”loose” and the pto-shaft Will not release! Do you have any idea what the problem might be? Best regards from Sweden (apologize for my english writing)

[@oskarlago1368]

Just to clearify! When I adjust it to maximum it still won’t release the pto-shaft and it’s like there is no resistance in the pressure plate!

[@manfromthemist1958]

Hi Oskar, a couple of questions, have you got a manual for your tractor? have you set the PTO clutch cover adjustment screws to .070", there are three of them in the clutch pressure plate. I got a video #34 which details the setting of the PTO clearance, it also detauils how to check and adjust the eccentric in the clutch pedal to obtain the correct clearance of the PTO adjustment screws to plate when the pedal is held in the check position lats know how you get on many thanks for watching Barry

[@oskarlago1368]

Thank you for a quick answer! Yes I got a workshop manual and everything is correct and the three screws are adjusted to .070’’! I’ve read about a guy with pretty much the same problem and he found out there were pins under the ”lifting-forks” on the pressure plate that had segares of! Which made no resistance in the clutch! What do you think about this?

[@oskarlago1368]

”Sheared of”

[@oskarlago1368]

When the adjusting screw on the pedal and the excentric screw is adjusted to maximum it is still not enough to disengage the clutch and the PTO

[@CORRIGEEN71]

You didn’t have to split the tractor? Last time I did one I split the tractor??

[@manfromthemist1958]

cheers Corrigreen, you're right you don't need to split the tractor, it depends on your circumstances and resources as to which way you approach the job thanks for the comments and your support very much appreciated barry

[@usefulcontent9894]

What was the make?

[@manfromthemist1958]

@@usefulcontent9894 the tractor is DB990 and the clutch is from Barclay williams (no manufacturer on it)

[@colmanlong1032]

another very well explained video.

[@manfromthemist1958]

Glad you liked it! thanks for watching Barry

[@wullieanderson3117]

Great video , as usual .

[@manfromthemist1958]

cheers Wullie thanks for the support barry

[@polleke038]

That is a great video, thanks

[@manfromthemist1958]

Glad you liked it! thanks for watching Barry

[@polleke038]

I feel very honoured. The explanation is very clear and I am very happy with it. Thank you Barry.

[@manfromthemist1958]

@@polleke038 Hi MJP, I very pleased I was able to help you and that you found this usefull, keep up the go work on your tractor Barry

[@polleke038]

Thanks Barry, I will. Kind regards Marco.

[@martinclayton2746]

Twos speed pto l do my next summer pump working now starts with using easy no Mc hammer used took me over year to do So there's no hurry good luck watching This likely lad started

[@manfromthemist1958]

Hi Martin, nice to hear your tractor is progressing, many thanks for watching Barry

[@jmiller3605]

Love the rant lol

[@manfromthemist1958]

got to let off steam, it's not healthy to bottle it up. thanks for watching Barry