350B Fan Belt Replacement

[Kaiverol]

I have my front end torn apart (rad, water pump) and think I should replace the fan belt while I can. Reading other posts, the sliding hydraulic pump disconnect coupler and lever are often seized and mine was no different. However, a bit of penetrating oil and waiting days to let it do it’s job may have helped. While everything still seemed seized a bit of tapping and leveraging slowly got both parts loose and moving well.

I was expecting that once I was able to slide the splined coupling away from the engine side adapter fitting there would be a gap opened to allow a belt to slip through. This was not the case.

I’m going to assume now that I will need to remove the hydraulic pump and remove the splined shaft between the pump and the larger splined shaft on the engine. Or does the pump shaft slide as well?

There is quite a lot of oil on the front of the engine, but I don’t know where the likeliest leak is? My unit has power steering, but the reservoir was empty. Therefore, the ps probably wasn’t working and no doubt needs plenty of overhauling. Just mentioning that to ask if it is worth it to work on it as well and anything else?

[Timbertime]

You could use a Accu-Link segmented V belt they work quite well.

[LeonardL]

There should be a "C" clip on the shaft that you need to remove and this allows the shaft to slip back as well. You should address your steering pump since it is driven by the gear train on the front of the engine. If the pump ever seizes from lack of oil then it can cause damage inside the gear train or break the front cover. You can either overhaul the pump / replace it or take it out of the system and put a plate over the hole in the cover. Then you will have manual steering. These were prone to have tank leaks and I would suspect yours is no different.

[Kaiverol]

Thanks Leonard. I’ve seen the “C” clip on the parts diagram. Will remove it and see how it goes. Worst case, I will remove the hydraulic pump, since I plan to drain the reservoir for some leak repair there too.

I could see going with the segmented belt too if I wasn’t this far along already.

It’s good to know about the risks with seizing pumps. I will pull it apart. And I will check out the tank for issues.

[LeonardL]

It's been a long time since I last changed a belt using the separator. I usually have a machine down to the point that it's easy to replace the belt since the pump assembly is off. In my reassembly I will do one of two things. I will either free up the existing lever system and use anti seize on all the parts in hopes it won't seize again or I will replace this older system with the newer style that does away with the lever system. Depends on the customer and parts availability.

This separator was designed more for cold condition starting than it was meant for belt replacement. It separates the hydraulic system from the motor so that the starter isn't having to pump very cold and stiff oil through a very cold and stiff system. This was rarely used for that reason and became more for belt replacement. But then the belts never required changing so they seize from lack of use. These Deere OEM belts last a very long time if nothing happens to damage them. I see machines even today with the original belt from the factory still on them and still okay after fifty years.

I am not a big advocate of the segmented belts. They work and some guys have great luck with them. I haven't had great results however and have ended up replacing the belt with a standard belt anyway. But that's me... I'm not going to condemn them for anyone who wants to use them.

There is a way to do away with your steering pump if your machine has a reverser with the later model valve body installed. In other words it will depend on the serial number break on these "B" model machines. The later models use a port on the valve body that the "C" models use to engage their steering clutch packs. The port is located on the side of the valve body and uses residual pressure from the accumulator to activate the steering clutches. The later "B" model machines were the first machines to use this port in order to activate the power steering rather than having a system pump to supply the hydraulic pressure to do this action.

[Kaiverol]

Main reason why I thought I would replace the belt was because it looked old and greasy. I didn’t give a closer look. If these belts can last as long as you say, I’m not as concerned.

Since my last post I was starting to contemplate if I need to replace the front crank seal (wondering if it is a source of oil leak). If so the belt will be accessible again, but now I’m just more focused on leaks.

I really haven’t been able to determine my exact serial number, but doubt I would have the newer valve body.

[LeonardL]

I didn't mean to imply that you shouldn't or don't need to replace your belt. If you are there and have an easier access to the belt and if it looks like it is old and greasy then by all means replace it. The point I was trying to make was it is because of the longevity of Deere belts that these separator mechanisms seize in place. They never get used so they rust in place was the point I was trying to make.

As for your front crank seal... I would replace it as well. Again if you are this close then it is an opportune time to change it as well. Along with anything else on the front of the engine that is hard to reach once you have reassembled everything.

[Kaiverol]

No, I didn’t take it as don’t change the belt. I’ve said in previous posts that I am not a mechanic and virtually everything I do is for the first time. Therefore, I don’t know things that you and others take for granted.

Some of the time I am trying to avoid doing some work mostly because I am worried that I am going to get myself in trouble and break things or not have the skills or tools to fix my mistakes. But I need to step out of my comfort zone, so that the repair is not just bandaid style.

Your recommendation to fix other parts on the front end is appreciated and the type of advice that I need to not be afraid. Often, the time I spend fretting about doing something, I could have just done the whole repair.

Heading out any minute to pull a few more parts apart. And loving it!