Broken ZF-Synchroma-Getriebe Gearbox and Need Replacement

G'day Kiwi Bloke,

Is there some reason why you cant just replace the box with something else, like maybe an Eaton road ranger with the appropriate number of gears? A lot of truck stuff is reasonably generic when it comes to mating motors to gearboxes.

As for the gear failure, I'd suspect maybe an alignment problem, perhaps the teeth weren't quite the right angle when meshing the the opposing gear. Or perhaps a preload(lack of?) issue?

I suppose there was the appropriate type and amount of lubricating fluid in the box?

This is a pretty serious piece of kit from what I can gather, so it would want a gearbox that was fairly substantial.

My Tuppence worth

Unfortunately this is not a generic fit. We did look at finding a gearbox similar but there are space restrictions and from what our engineer says, the box lies on its side not upright as such.

The gears were blued so I would have expected any alignment problem to have displayed itself during that process.

Yes we did have enough oil in the box when we ran it.

You can see why this is a bit of a dilemma.

Thanks for your help anyway.

Spotted this on the Grove website regards the current gearbox used on the TMS800 series

Roadranger Ultra Shift 10 speeds forward, two speeds

reverse. Two speed auxiliary transmission. Used with

ISM450 "On Highway" engine.

Roadranger manual transmission with 11 speeds forward,

three speeds reverse. Used with QSM 402 "Off Highway"

engine.

They use a Cummins engine.

I got that from here

http://www.manitowoccranes.com/MCG_GRO/Home/EN/BrandHome.asp

Hope that helps.

Thanks for that. I will get the engineer to look at that site and see if he can find what he needs. Unfortunately this crane is probably 20+ years old so I may have to look in a scrap yard.

Thanks for your help.

Kia ora,

you could try Don Mathias - the Machine Shop, here in ChCh 03-981 2889

He builds rally Toyota gearboxes (for years now), he may be able to help build you something reliable.

have you analyzed the original broken gear box? Was the remade gear of the same

gear material like this? strength of steel, hardening, etc? Fault analysis?

Why did the original fail? As someone said, a shift or other clearance in an axle/bearing by gradual wear can put an intolerable stress on a part, making the old one fail, and break the new ones right away.

Can the gearbox be removed in toto and analyzed by a capable gear specialty shop, which migt have to be found in a major port town with repairs to hundreds of cranes over the years.

When a gear wears out/fails more often than not the mating gears are shot as well, if not damaged by the destruction of the first gear. So I would look really hard at the rest of the box for forensic clues. Also, heat treating gears is a bit of an art form. Most are not fully heat reated, but only the teeth are induction hardened and the core of the gear is softer to allow for better toughness. So how do you know you "heat treated it to spec"? Do you have the original machining drawings from Grove or something? 20 year old Grove cherry picker cranes are thick on the ground here in the Houston area, every oilfield fab yard has one at least. Try contacting Stewart and Stevenson here in Houston. If they can't help you, you are beyond help.

Hi Kiwi,

You need to use E36 steel, machine and case harden to 45-55 Rockwell C with 0.1-0.3mm stock. Temper to 40-50 Rockwell C then hard finish...

Shout if you want more details, I could probably put you in touch with someone who makes them,

Cheers,

Saffa.

I believe Manitowoc in the US may have manufactured this?????. At one point they had a number of companies, Cranes being the biggest then icemakers, ship yards, one I believe was grove. Not sure. Gear box sounds German.

The have been liquidated and selling off.

I had worked at a large Machine shop where they Manitowoc jobbed out some of the gearing to. but I'm sure there is more than just machining the gear. such as hardening.

But there sounds to be something else that does not sound good.

p911

Kiwi,

6 minutes of operation is very little time working to justify breaking only by use of incorrect material or heat treatment.In my experience I believe there has been some kind of geometric errors, such as gear backlash or deformation due to thermal treatment, as well as using old gear pair. The ideal is to make the two gears (as opposed to shaft and main shaft), check the backlash gearing, something around 0.25 mm in the tooth flank and make sure that no play x 0.3 module gear between the external diameter and the root diameter of the gear pair. In many cases the material is SAE 8620 hardened and tempered, with around 1mm depth and hardness around 60 RC.

I got the information about your gear box and I will forward it to one of my buddies that is experianced with this type equipment repair. He owns a fairly large mechanical/civil/ construction co, a machine shop that specializes in building high performance engines as well as one of the largest scrap and equipment bone yards I ever saw and he also planted about 1500 acres of cotton and/or corn until he gave farming up a few years ago. I have saw some fairly hard to come by drive parts and gear boxes come out of that scrap yard and I bet there are a least 5 old Grove cherry pickers/cranes back in one corner or the other of that scrap yard.

If anyone I know can find the gear box you need it would be this guy's foreman/shop mechanic that oversees the heavy equipment repair shop and he probably knows more about cranes, new, heavy tractors, and hydraulics etc than I would ever care to know. I got to know this guy when working with him doing the welding and fabricating parts to repair and refurbish all of this equipment while he handled the repair of the drive trains, gears, brakes and mechanical side of the work.

If I can spot something or if the mechanics reconize this type box and gear as a hard one to repair they might know where some help can be obtained for this stuff.

I have a new old stock hydraulic transmission that I bought from the mill when we tore down the old chicken crane in the wood yard I was told it has 12 forward and 12 reverse speeds but I can't remember the name of it. This is a very compact gear box and I also have the main comutator for the swing section of the old crane and that is a pretty lagr large piece of copper. The comutator has never used and it is brand new old stock it also has new brushes and brush holders and all the other bells and whistles.

I will put this gearbox information on my "to find" list and look around the North Georgia scrap yards to see if I can locate one while I am looking for other stuff. i will also forward the request to all my scrap and mechanical contacts to keep an eye out for anything like thi

Hello all forum posters,

Well on arriving at work this fine monday morning I found all your messages of help sitting in my inbox.

First let me say "Thank You All".

You have all given me lots to chase up and my boss is very pleased. Info came from as close as my southern "cuzzy" here in Christchurch,New Zealand and as far away as the States.

I do believe you are all right in the statements about matching gears and misalignment due wear over time etc. Now to get my boss to register that issue and resolve it may be a bit of work. May be better for us to get a whil;e new box.

Again Thank You all for your help and we will chase up the info you have given us.

Cheers.