I have rebuilt several of these Tuff Torq trans-axles out of the 4x5 series machines. Depending upon your mechanical skills, its not a extremely difficult undertaking, but it is one which requires reasonable mechanical skills and a decent set of tools as well as a good place to work on the machine. You wouldn't want to undertake the process outside in the dirt, that's for sure.
Generally, these rear assemblies leak from a couple of different places including, but not limited to;
1. The differential shaft seal, which because of the function of the shaft's partial rotation, it works the seal out of the housing and causes quite a leak. If this is leaking, it generally will be on the left side of the housing, towards the rear.
2. PTO Shaft seal on the Mid PTO.
3. Gaskets between the transmission and the main assembly.
4. Swash Plate seal (packing as John Deere calls it) on the upper right side.
5. Any of the other seals or case joints can also leak, but they tend to "drip" more than be a serious leak.
Undertaking the repair, how difficult is it?
The dealer is correct, there is a lot of labor to rebuild and repair this correctly. Depending upon the actual source of the leak, the entire rear assembly may or may not need to come out of the tractor. There are several stages of the repair where having another person or equipment to lift large heavy items is going to be necessary.
On a scale of
1 to 10, with
1 being a very basic repair like replacing the fuel filter and
10 being the most difficult, such as a complete Yanmar engine rebuild,
I would place the
proper repair of the leak and assessment of the Tuff Torq unit at about a 6.5.
A
complete disassembly and rebuilding of the Tuff Torq unit is more like an 8 out of 10.
Tools / Items needed to perform this repair include;
Torque wrenches (1/4" drive and 3/8" drive)
Snap ring pliers (internal and external)
Floor Jacks and Jack Stands
ATV / Motorcycle or Transmission Jack for handling the rear assembly intact
Chain Fall, FEL or other way to lift the rear end assembly complete.
Sockets, ratchets, extensions, etc. a good assortment in SAE and Metric
SAE Wrenches / Metric Wrenches
Pry Bars
Precision measuring mechanical tools
Impact guns make the disassembly much faster but be careful using for assembly
Good clean, well lit work table area to keep parts organized
Good Lighting
Take LOTS of pictures as you take things apart so you can remember how they go back together.
Containers for keeping all of the assembly hardware organized as there are a lot of bolts and its critical they are used where they belong or damage can occur.
Power Washer / Air cleaning from leaf blower or compressor
Realistic Repair Estimates, assuming the leak is a typical problem and not something more advanced
Parts only
I would say the $100 for parts assumes that just a few seals and the case RTV sealant are replaced and that is very optimistic. Depending upon the hours on the tractor, you will want to check for wear in many of the hard parts, such as thrush plate, bearings, gears, shims, seals, etc.
The last one I rebuilt, I replaced the PTO clutch as well as all seals and gaskets and I think I had about $750 in parts. Of that total, the PTO clutch is about $450 of it (or was, parts have increased in price so its likely more now)........
Labor to repair, based on actually having repaired several of the K-91 Tuff Torq Assemblies in the Deere 4x5
When you have the machine disassembled, its foolish to not deal with the other issues which often happen to these machines, to avoid the labor of making another repair shortly after this one is completed.
26 labor hours seems extremely high to me, as one who is familiar with these machines can have the operator platform off the machine and the rear end assembly out of the machine as a unit within about 3 hours and that's not working recklessly fast. From there, further disassembly of the components would begin, which is where the hours can add up quickly,
Here are the time estimates from my actual experience;
12 to 15 hours to remove the assembly, properly clean the parts, check for the wear on items which often require replacement and make the repairs and get it put back together and functioning properly.
The last one of these I repaired, I took my time and power washed everything as it was taken apart, then painted everything as it was put back together. I also replaced the fuel tank screen, fuel lines, repaired wires by heat shrinking them, etc. Even then, I doubt I had 22 hours in the entire project.
I think a repair estimate of 15 to 18 hours to be thorough and check the components and reassemble carefully after cleaning, etc. would be more in line, than 26 hours.
If i were simply working to get the leak repaired, even then, I would guess the total labor should be no more than 8 hours and could be less, depending upon the cause of the leak.
Suggest performing other "preventative repairs" while working on this issue.
It's not a good idea to repair just the source of the leak as there are a number of seals, gaskets and packing which will develop leaks, after all, this is a 20 to 25 year old machine. Also, when the operator platform is removed, its a good idea to replace the fuel tank pickup screen and sending unit O ring. The pick up screen in the tank is usually rotted and collapsed by now, which will eventually cause the fuel pump to fail. Its better to address these issues when you have this torn apart than to get it back together and then have to disassemble it again.
Also, its not uncommon to find that mice have made nests under the operator platform in all of the grass which will be packed up in there when you take it apart. The mice also chew on the wires for the harness under the seat, which needs to be checked as it is the seat safety switch, fuel tank and fuel pump as well as the tail lights, etc. I have pulled out 3 packed 5 gallon buckets worth of the grass packed up under the operator platform. This makes the Hydro unit much harder to cool, which isn't good for the machine.
These other repairs and preventative issues will add labor hours, depending how in depth you get.
Should you repair your machine or buy a Used Tuff Torq K-91?
The only way I would consider a used rear assembly is if the case was damaged beyond repair, which doesn't happen very often. Otherwise, you are likely buying a case which will leak in the future if it hasn't been rebuilt properly. I would rather stick with the case from your machine, you know how that's been used.
Get the Technical Service Manuals as it makes the process much easier and avoids making critical mistakes.
Tuff Torq has an excellent Technical Service Manual for their rear assembly. Also, you will need a Deere Technical Service Manual in order to properly make this repair. If you are confident in your mechanical skills, this isn't a terribly technical or difficult project, just one which requires time and patience to do correctly. Make sure to get the Authentic TSM and not the generic versions sold on Ebay, etc. Why do you need the TSM's?
- Torque Specifications
- Tolerances and wear standard amounts to check thrush washer, pump output, etc..
- Proper disassembly and reassembly sequences and procedures
It is critical you have the TSM to properly torque the numerous bolts and fasteners as you are dealing with aluminum case components and do NOT want to crack any case pieces or break off any bolts. One of the first one of these i rebuilt, I broke the last bolt off in the case by not torquing it correctly and I spent several hours getting the broken bolt out of the case. In fact, I spent more time repairing the broken bolt in the case that it took me to get the tractor put back together. I have also seen improper torquing cause the case to crack and you do NOT want that to happen.........
Is the machine worth repairing or is it trade in time?
One last thing, if you are going to ask yourself, is the machine worth putting the money into for the repair? If the machine is in good operating condition, then I say "Absolutely, the machine is worth making the repairs". More details about the hours on the machine, any other issues that might need repairing and the condition of the hood, side panels and other items on the machine are needed to know its likely value.
Consider repair shops other than the Deere dealership
You may want to check with local small engine / lawnmower repair shops about undertaking this project. Many will have worked on these Tuff Torq assemblies before and I wouldn't be surprised their repair estimate would be much less than the amount the Deere dealer told you. Just make sure they can handle such repairs as they will need the Technical Service Manual and a shop which handles garden tractor drive assembly repairs. Ask them how many of these they have repaired, as the Tuff Torq K-91 is used in many of the heavy duty garden tractors made in the 1990's and into the 2000's.................
Parts will have to come from Deere
One last point, you will have to get the parts from a Deere dealer. While Tuff Torq does have their own parts department, they are required to direct those customers with Deere machines to their local Deere dealer.
In closing......
Let us know how we can help. There is a lot of experience with these machines among the GTT membership.
We can definitely guide you through the process to help you get this repaired, if you have reasonable mechanical skills and a good place to work on the machine. If you don't generally perform the machine maintenance yourself, then I doubt you will want to dive into this repair project.
