I can't figure out what these Transformers are?

OK, so I bought a set of four Transformers from Toys R Us in Times Square in 2001. I do still have their packets and instructions but they are boxed away in storage.
Since I've recently got back into Transformers I pulled them out of my toy collection box to put on my shelf, but I can't for the life of me remember who they are - I've even browsed the toy gallery A-Z to see if I can spot them but I've had no luck.
They are all Autobots and combine together to create one huge bot, very very similar to Constructicons in that they are all work vehicles and combine together.
The one with the larger head (the leader if I remember) is an Orange Digger/Shoveler (similar to Cybertron Landmine).
Two are very similar and form the legs, one is a Green Digger with an arm, the other is a Red Crane with a hook on the end which is the combined bot's gun.
The last is a Yellow Dump Truck, the dumper section comes off to form the combined bot's shield.
The main reason I am posting this is that I can't figure out how they fix together to form the giant bot, and can't find any images that would be a guide as I don't know what they are called.
I can post images if they are needed, but I was wondering if anyone knew what I was talking about? Online instructions would be awesome too!
Thanks.
Since I've recently got back into Transformers I pulled them out of my toy collection box to put on my shelf, but I can't for the life of me remember who they are - I've even browsed the toy gallery A-Z to see if I can spot them but I've had no luck.
They are all Autobots and combine together to create one huge bot, very very similar to Constructicons in that they are all work vehicles and combine together.
The one with the larger head (the leader if I remember) is an Orange Digger/Shoveler (similar to Cybertron Landmine).
Two are very similar and form the legs, one is a Green Digger with an arm, the other is a Red Crane with a hook on the end which is the combined bot's gun.
The last is a Yellow Dump Truck, the dumper section comes off to form the combined bot's shield.
The main reason I am posting this is that I can't figure out how they fix together to form the giant bot, and can't find any images that would be a guide as I don't know what they are called.
I can post images if they are needed, but I was wondering if anyone knew what I was talking about? Online instructions would be awesome too!
Thanks.