Fiat 70CI. Repairs, modifications and stories.

[nutwood]

Thanks nutwood
I'm going to have a look at it this weekend so I will get to see what it is actually doing but for the price I'm paying I don't mind if iv got to spend some money on it if it does need work. The one thing I have noticed about this model is that it is very hard to find information on

Well, that's another way to look at it. In a way, I'd rather purchase a machine with a known problem, pay an appropriate price and then fix it myself.
I purchased my dozer with recently replaced steering clutches and thought I wouldn't have to worry about them for years. Within six months I was pulling the machine apart to replace them. They were new all right but the mechanic who'd done the job had omitted to bend over the locking tab on the pinion shaft. Nut came off, flange started rattling about, oil flooded through into the clutch. Not a pretty sight!

 

[AusDave]

Sorry to butt in but does anyone have any info on bt7d dozers and what they are like as I'm looking at buying one at the minute also how hard it is ( or simple ) to adjust the turning clutch

Hi Fergie.

I used to own a BT7D in North East Victoria many years ago. It has a later model, smaller, quieter, higher revving engine than the 70CI which I also owned as well. (I wonder if your BT7D is our old machine?)

We never had any problems with the motor, final drives or steering clutches in the BT7D but we did in the 70CI.
The BT7D as well as having a different motor, has a different final drive configuration. Instead of having the pinion from the steering clutches drive the bull gear directly, there is an intermediate reduction gear/layshaft assembly which is driven by the steering clutch pinion and then drives the bull gear. This spreads the wear and the load on the final drives and they lasted very well for us. I can't remember for sure but I think it may have had an oil filled main clutch too.

All in all it was a good machine. The 8 foot semi U blade held a lot of dirt and we had a good set of rippers on the back.
I think you can get a lot more info on these particular machines from GW Tractors as mentioned in this thread.

AusDave

 

[nutwood]

Hi Fergie.

I used to own a BT7D in North East Victoria many years ago. It has a later model, smaller, quieter, higher revving engine than the 70CI which I also owned as well. (I wonder if your BT7D is our old machine?)

We never had any problems with the motor, final drives or steering clutches in the BT7D but we did in the 70CI.
The BT7D as well as having a different motor, has a different final drive configuration. Instead of having the pinion from the steering clutches drive the bull gear directly, there is an intermediate reduction gear/layshaft assembly which is driven by the steering clutch pinion and then drives the bull gear. This spreads the wear and the load on the final drives and they lasted very well for us. I can't remember for sure but I think it may have had an oil filled main clutch too.

All in all it was a good machine. The 8 foot semi U blade held a lot of dirt and we had a good set of rippers on the back.
I think you can get a lot more info on these particular machines from GW Tractors as mentioned in this thread.

AusDave

Interesting about the different final drive arrangement. The steering clutches seem to be a weak spot on the 70CI based machines. I wonder if Fiat were acknowledging this? Presumably having an extra level of reduction would reduce the load on the clutches but I reckon the biggest help would be if the new design did a better job of keeping oil out of the clutches. I'll add some images of what my clutches looked like the last time they were out.
The thing to remember when looking at the images is that, firstly there's meant to be teeth on the outside , but also, my machine was not leaking oil in any noticeable amount. I keep the bungs out of the bottom of the clutch housings and it was rare to notice a drip of oil. I think some was dripping from the boost cylinder above, the odd drop found it's way past the seals and over time it all found it's way into the clutches. Once the oil gets on the plates they start to let go. First sign is you pull the right clutch lever (seems the left almost always goes first) and both tracks stop under load, then it gets sluggish when turning right under any condition. Finally all you can do are anti- clockwise circles. At this point you pick a nice place for dozer dismantling as you're not going anywhere, although I did move mine a short distance with a tractor and a chain on one side of the blade.

 

[Jeembawb]

Where did all the teeth go nut wood? Is there a fiat tooth fairy or did you find them in the bottom? I'm thinking that's what mine will look like

 

[nutwood]

If you look at the top left image, that black blob slightly below centre will be some of them. Many others will still be inside the drum. The oil and ground up bits of fibre plate sort of merge together to make a thick goo.
I'm looking forward to the images of your repair. Between us we should be able to put a pretty comprehensive collection of "fixing Fiat clutches" images.

 

[Garrie Denny]

No pressure other than the lower hole spilling out water if i overfill the rad above the strainer basket bottom level.

 

[Jeembawb]

No pressure other than the lower hole spilling out water if i overfill the rad above the strainer basket bottom level.

What do you mean Gaz about the lower hole - do you mean the water pump?

 

[nutwood]

Where did all the teeth go nut wood? Is there a fiat tooth fairy or did you find them in the bottom? I'm thinking that's what mine will look like

Occurred to me to ask; would it be any help to you if I posted the various images I have of my steering clutches coming out? I was thinking it made more sense to give you a clear field as I didn't really take my images in a sensible order to show how the job went but if it'll be any help to your project..?

 

[Jeembawb]

Occurred to me to ask; would it be any help to you if I posted the various images I have of my steering clutches coming out? I was thinking it made more sense to give you a clear field as I didn't really take my images in a sensible order to show how the job went but if it'll be any help to your project..?

For sure nutwood if it's no trouble. And if there are any pertinent pics missing from your procedure I will make sure I get a pic of that for the series. I'm trying to find a truck/trailer hub to use for the base of a homemade slew crane / jib that I am mounting on the back of an old patrol wagon that I have chopped the back off. I figure if I can lift the bits off the dozer then swing em round to put on the back of the patrol to take em off the track and down to the shed, it's gonna make it a little easier. Raining today but

 

[Garrie Denny]

There is a hole approximately the size of 1/4 inch copper looking at you when your in the operators seat, its its approx 3/4 of an inch below the screw down radiator cap level, i can only imagie it was for a expansion pipe when the machine gets to operating temp as this is when it dribbles out for a short time if i overfill the radiator (to overflowing.)

 

[Jeembawb]

There is a hole approximately the size of 1/4 inch copper looking at you when your in the operators seat, its its approx 3/4 of an inch below the screw down radiator cap level, i can only imagie it was for a expansion pipe when the machine gets to operating temp as this is when it dribbles out for a short time if i overfill the radiator (to overflowing.)

Yeah Garrie - that is the overflow / expansion tube hole - if yours doesn't already, it's supposed to run along the bottom of the top header tank and then half way (or more) down the LHS of the radiator & dumps to nowhere. This pretty much makes it "the level" in the radiator header tank. Quite common for them to rust up & block like mine was.

 

[Garrie Denny]

Question. What are the top and bottom covers made of on the radiator im thinking mine has to come out and do some soldering ?.:notworthy

 

[Jeembawb]

Question. What are the top and bottom covers made of on the radiator im thinking mine has to come out and do some soldering ?.:notworthy

JB Weld it Gaz

 

[Garrie Denny]

I havent pulled it out yet, is the core steel or brass,copper, what about the top and bottom tank ends ?

 

[Jeembawb]

I havent pulled it out yet, is the core steel or brass,copper, what about the top and bottom tank ends ?

Not sure mate - most radiators will be brass core (run a file over it & you will soon know) & the tanks are gonna be cast iron - be carefull removing it - one of mine looks to have been roughly repaired (cast iron welded) a few times where all those plates bolt on the sides - i would say that the bolts might have been rusted in there & someone was a bit heavy handed removing them & parts of the casting have broken away around the bolt holes.

 

[Garrie Denny]

Thaks for the heads-up, ill let you know blow by blow description when i do it and we;ll all have an insight to the radiator drama of the 70ci. (ill take pics and post).

 

[nutwood]

Top and bottom tanks are cast iron and I'm fairly sure the core's brass. I've had mine out and repaired. Pesky branch snuck in past the engine and poked a hole in it. Bit of a pain pulling out as you have to drop the hydraulic pump but I just took it to the local radiator place and they soldered it up. They moaned a bit about how old the core was but it still soldered up fine and has gone for years since. I think I've also soldered up a smaller hole or two myself along the way.
Cores are still available for them at not unreasonable prices, considering the size of the radiator.

 

[Garrie Denny]

What is the seal on the core and top and bottom i wasnt aware you could solder to cast iron, steal, stainless steel not a problem but cast ? ill have to check on that one, thanks Garrie.

 

[Jeembawb]

What is the seal on the core and top and bottom i wasnt aware you could solder to cast iron, steal, stainless steel not a problem but cast ? ill have to check on that one, thanks Garrie.

any help?

 

[Garrie Denny]

Yes thanks,it looks like the core fits into the top ad bottom panels but am wondering are they soldered where they join or some sort of mechanical seal ?