Sheppart steering for DM690. Need help.

[Vladislav]

I had an issue with that steering gear when purchased the truck. But put myself into even larger issue due to lack of attention.

Originally there was obviouse damage to the input shaft seal. And also the top cover bolts were partially removed and those which hold the joint bracket too. So looked like somebody tried to fix the leak but hadn't. After I fired up the engine and drafted some fluid into the reservoir the seal (or the place it supposed to be) started spitting oil if I spinned the steering wheel. I drove the truck for 20-30 meters to get it into my property from the street. Than parked for better times. Recently a need showed up to relocate the truck. I had a couple of similar gears off R-models in a shed and figured to just swap the unit. We put plenty of efforts to pull the Pitman arm off the shaft and have extracted that darn weighty piece of iron from the chassis.

And only when it was off I could find out although general look was very similar the DM unit appeared notably larger than those I had off R's. 

This way there's a need to swap the seal at least or revise it fully (that's preferrable). One moment I dislike we had to heat up the Pitman arm by torch since it didn't go otherwise and I now worry on the condition of its shaft seal either. The shaft hasn't become really hot and I saw no smoke from that spot but seems reasonable to make the check or a swap.

So the questions are:

Can anybody identify the model? I haven't found any serial number/stampings. Cast digits only.

Is there repair manual avalible?

What are the part## for both input and output seals?

Thanks in advance, any input is very appreciated.

[Vladislav]

[mowerman]

This is where mine was good luck  It was right at the top of the triangle.

[Vladislav]

Looks very similar. Could you locate any spairs for it? I just missed that part in your whole long story. Even tried to rifle through but ran outta time.

[mowerman]

Yes, somewhat  limited but still out there I got my parts from straight line  steering in San Jose California 

[mowerman]

Oh wait a minute,,,, are you asking if I have leftover parts???

[Geoff Weeks]

Vlad,

that seams to be a "Three number" series Sheppard.  It might (likely) has the three digit number cast into the housing on the one side you don't have a picture of.

The complete number includes a sub-model that will be stamped into the face under the spacer that is held on now by one bolt on the output shaft side. 

I think I have posted the manual for these, maybe in @mowerman thread. If not I can go looking for it in my files and post again.

These boxes tend to leak at the input shaft, and that is a high pressure seal. The grease zerk on the side is there to pump grease in and force dirt out of the outer seal before it can damage the inner seal.

 It is real common after they see a lot of years use, for the shaft to wear to the point it will not "take" a seal, and then the hard shaft has to be replaced or welded and re machined and then hardened.

The output shaft seal is in the low pressure (return side) of the box and doesn't often leak even when the bushing behind it is well worn.

I think 592 is the largest in the series, I don't know if that is what you have or not. I don't think it is the earlier two digit series.

I think parts are still available but it has been 10 years or more since I got some.

[Geoff Weeks]

Looks like it:

592 box

[Geoff Weeks]

Here, attached is the manual.

Sheppard-Manual-92-Series.pdf

[mowerman]

Well, you beat me to it. I was going to say I could post pictures. I still have all that stuff on my computer and yes, I think his number is probably on the opposite.Side

[Vladislav]

21 hours ago, mowerman said:

Oh wait a minute,,,, are you asking if I have leftover parts???

Bob, no, no leftovers. I suppose you used all needed parts and I also suppose I will need the similar ones exactly. A question I'd ask regarding that haven't you saved the parts order or the invoice? I could use the seals ## from there and maybe a few other items.

[Vladislav]

19 hours ago, Geoff Weeks said:

Here, attached is the manual.

Sheppard-Manual-92-Series.pdf 2.5 MB · 1 download

Many thanks! Now I'm not blind!

In general this style of power steering gear is familiar to me. I rebuilt a few integral units for Mercedes cars and G-wagens. Also a shaft with semi-round threads and circulating balls.

Still not sure on rightness of identification of my box. I could locate the stamping today. There in the triangle near the adapter plate. 87H1540 and ST5 is written there. Also cast text can be read as 592S5-6 what may be count as 592-something. Does this guess seem correct?

[Vladislav]

Also there's a bit of results of on-line search. Repair kit for 592 is represented by Automann (China or Turkey?) 465.4024 or (possibly) another option here: https://suntransmissions.com/products/complete-gear-seal-kit-transtec-rh-sheppard-592-series-3-4-5518091-8305?srsltid=AfmBOorts27v7nDsEdYNOaM7l9WNbOqG15ELRbp1TAigeXZKWd2O1K_U

Do those kits look as what could/should be put into 592?

[Vladislav]

Just now, Vladislav said:

 Also a shaft with semi-round threads and circulating balls.

 

Upps, I'm wrong. No balls in the thread in Sheppard. Even much simplier design. Those balls are the most of headach assembling Benz boxes.

[Geoff Weeks]

Yeah, it is a 592S, the sub model you don't need to know most of the time, it has to do with indexing the output gear and the pitman shaft.

Those repair kits should work. Most times I only need high pressure shaft seal. 

The big question is if dirt has got into and scored the input shaft.

When I've done mine, the only time I went deeper in was when the bushing supporting the pitman shaft was worn enough that I had to pull the guts out and replace the bushing and output seal.

Many time I can replace the input shaft seal with the box in the truck and the output shaft connected to the steering.

[Vladislav]

13 hours ago, Geoff Weeks said:

Many time I can replace the input shaft seal with the box in the truck and the output shaft connected to the steering.

That could be my way to go if I knew the design of the insides than. But those spare units put me onto wrong rails. Also DM has the box inside the frame so I haven't seen the whole thing until pulled it out.

So far my idea is to take the unit apart carefully and investigate the insides. Input shaft outside seals are needed definitely but seems they could be located just by the size. High pressure seal is another story. So seems I already have something more to put my hands on. 

Many thanks for the info support.

[Geoff Weeks]

un bolt the top ring of bolts, then rotate the input to force the input and top out of the body. the "thread"on the input into the valve body is a multi start thread, so try and observe what position the flat on the spline is in when you put it all the way out, so you can put back the same way.

It doesn't effect the workings of the gear, but the steering wheel will be "off" if the flat on the input is in the wrong position when you go back.

You need enough room over the box to be able to thread the thing all the way off, but the rest of the gear stays put in the truck.

once the top is out on the bench, you drill out the retaining pins and un screw the gland nut to remove the shaft from the top cover and replace the seals. No need to remove the whole box and it doesn't help having it out, as long as you have room to work with it in the truck.

[Geoff Weeks]

before removing the top cover mark its orientation to the main body, it has to go on so the relief adjusters will hit the relief ball when the box is turned to the end of its travel.  A coupla punch marks will help make sure it is on the correct way.

Edited 6 hours ago by Geoff Weeks

[mowerman]

No, I don’t have any parts to give away. I have a few leftover, but I’m saving them for myself. I do have a sector bushing that does not fit. I am hoping somebody could use it one of these days beside your boxes a lot different than mine and yes, that number looks correct. Of course you’re probably figured that out by now. 

[mowerman]

And yes, it looks like my sector shaft can be removed with the box inside the frame. I think I just have to take out the alternator. But I won’t have to touch it now.

[Vladislav]

4 hours ago, Geoff Weeks said:

before removing the top cover mark its orientation to the main body, it has to go on so the relief adjusters will hit the relief ball when the box is turned to the end of its travel.  A coupla punch marks will help make sure it is on the correct way.

Well worthy advices. Thanks. I'm not almost sure on the initial correctness of the top cover fit. A portion of bolts were already loose and that bracket for U-joint intermedial shaft was partially hanging in a wind. Definitely its correct position wasn't clear to me. Somebody tried to fix the leak I guess, tried removing the cover and than something went out or order. Do I understand right I could figure orientation of the cover by position of the relief valve pin? It must point to the relief ball right? Also I'd like to investigate the condition of the Pitman arm shaft seal as I noted previousely.

Honestly for the best scenario I would like to disassemble the unit completely, cover mating surfaces with steel lazer cut covers, sandblast and paint the housings, regalvanize hardware than put everything back together with new OEM seals. But the irony is I have one more Mack power steering box which is supposed to pass along that described path and that's a plan for distant future. And that yellow DM is wanted to be movable in the nearest couple of months.

[Vladislav]

Just now, mowerman said:

And yes, it looks like my sector shaft can be removed with the box inside the frame. I think I just have to take out the alternator. But I won’t have to touch it now.

That's an interesting thought on the output shaft to be removed with the box in the chassis. Not almost sure but possibly. On the other hand my most trouble was removing the Pitman arm. Taking the box out wasn't easy task too but we were 3 men crue for that deal. Thanks for taking attention to my question Bob.