d7e what changes ?

[broken1961]

what changes did they do to the engines from a low hp to the high hp, and can you tell me what year this 7 is, the serial number is 48a6842 ,thx Scott

[Old Magnet]

48A6842 is a 1966 model. Later the same year (48A6883-up) the Turbo changed to a #4S9706 assembly.
Rack settings were changed to 0.355" and used a 3H4861 Torque Spring (0.035"), a 6F353 spacer (0.049") and a 1S8883 spacer (0.010")

Used the 5M4238 Governor Group and 8M2250 Governor Spring (silver)

Full load RPM = 1200
High idle RPM = 1340

Net result 180 hp w/fan

The earlier models were more around 150 hp w/fan and 160 hp w/out.

[7upuller]

Hey OLD MAGNET,

You are a class act. You always take time to help, and you are vey knowledgable. Thank You for being part of ACMOC and the BB. It wouldn't be the same with out you. Now all you have to do is fix the government and our leader, what's his name? Thank you for being here. -glen

[Old Magnet]

Thanks Glen, appreciate that.
On that other matter, nothing a good running dozer wouldn't fix.....

See you Sunday.

[broken1961]

yes thanks for the information Old Magnet, i appreciate you taking the time to answer my questions, thxx again Scott

[u-joint]

i believe if one would research this out completely you will find many other changes beside a turbo and injection pump!

[Old Magnet]

The engine block changed at 6883, but that was to accomodate the new rear main seal design.
The rod and main bearings were changed from aluminum to plated aluminum.
The rod bearings were now 1/2" narrower on new rods.
New crankshaft to accomodate the seal and rod bearing changes.
Main bearings remained the same dimensions.
Pistons/rings remained the same.
Heads & camshaft remained the same.
The change to 180 hp was all in the rack setting. The turbo actually was changed back at s/n 6393 along with the change to horizontal dry type air cleaner and produced 160 hp w/fan (mistated as 150 hp earlier).
The governor group and spring did not change.

[tctractors]

Make no mistake those 48a tractors are just the best bit of Iron ever built by CAT, everything about them was to the top standard, the noise they make just shunting around is super to hear, pulling hard on a box (Pan) they bark to perfection,if you love CAT iron and have the Coins these are the boys to play with, well in my brain anyhow.
tctractors

[D6 Pete]

I would like to find a good set of track chains with good pads,, and rollers for my 48A ,, in CA would be good!.,, Where would be a good place to look ? Thanks for any help.... pete