What did you do with your GMT400 today...or yesterday....

[Big T]

No gasser unless it's dirt cheap

The prices justify my fixing up and painting the ‘94 and ‘99 diesel K2500s.

 

[jrsavoie]

I wish I would have kept the 98 and the 96

 

[Big T]

Installed a new CS-144 250 amp alternator today in the 1994 K2500 Suburban. Old one had given up.

 

[MrMarty51]

Installed a new CS-144 250 amp alternator today in the 1994 K2500 Suburban. Old one had given up.

You did save Your 6.5 diesel pulley ?

 

[Big T]

You did save Your 6.5 diesel pulley ?

I still have the old CS-144. It has the same size pulley as the new one. Also still have the original CS-130 alternator. I can compare the pulley sizes and swap if necessary. What’s the proper size pulley for the 6.5? Where do I take the measurement?

 

[MrMarty51]

Drove the truck to church today.
Total miles since last fuel stop was 96.
33 of that was daily in town driving.
63 highway.
Took 7.0 gals of fuel.
13.7 MPG average
Thats with a new ECM tune from Leroy. Told Him I would like 15 if its dooable and still have power to pull a boat/trailer max 5,000 pounds.

 

[MrMarty51]

I still have the old CS-144. It has the same size pulley as the new one. Also still have the original CS-130 alternator. I can compare the pulley sizes and swap if necessary. What’s the proper size pulley for the 6.5? Where do I take the measurement?

IDR the diameter across the ridges of the 6.5 pulley, It may be 2-5/8ths inch, IIRC.
I recently bought one from Leroy Diesel, I’ll get a measure of it.
I do know that at 70 MPH that the tach is reading just about directly on 2,000 RPMs with 4:11 gearing, or maybe its 4:10, I cant rememer alla this .

 

[Big T]

IDR the diameter across the ridges of the 6.5 pulley, It may be 2-5/8ths inch, IIRC.
I recently bought one from Leroy Diesel, I’ll get a measure of it.
I do know that at 70 MPH that the tach is reading just about directly on 2,000 RPMs with 4:11 gearing, or maybe its 4:10, I cant rememer alla this .

It must be smaller as the tach is reading much higher.

 

[Big T]

OK went out and located the old alternator and measured the OD of the pulley at 65mm. The OD on the alternator I just installed is 60mm. So looks like I need to swap pulleys.

 

[Big T]

I went and swapped pulleys and that was a mistake. I never even removed the cooling fan behind the pulley and now is is scraping on the alternator. Even worse, the lift pump is no longer working. This is a Walbro lift pump and it’s relatively loud. I’m hearing nothing and seeing no pressure on the gauge. I finally got it to start and the fan on the alternator is screeching. I’m letting it cool off before removing to inspect WTF went on.

 

[Big T]

I’m betting the lift pump is a fuse.

The rubbing fan issue is probably due to different configuration of the pulley. One that came off had a spacer built in on the back. The larger one did not. So that had the rim on the larger pulley pushing the fan towards the alternator, causing it to rub.

 

[Big T]

Pics show the differences in the pulleys. Needed to use the spacer behind the larger diesel pulley.

The fan is toast. I swapped in a smaller fan from the CS-130 and will try to separately purchased a new larger CS-144 fan. Got it back to working.

 

[Will L.]

Dag nab it whipper snapper! Sux that happened- but yes the right size pulley is critical for your engine because that alternator is where you get your tachometer. That tells transmission when to play nice and when to play mean.

So lost a alt fan but saved a transmission in time. Letting that thing slip gets costly

 

[MrMarty51]

Spacers is a mighty important factor when swapping components on alternators.
A good rule I go by is after setting the fan to the shaft, hand press the fan towards the alternator housing and see if there is proper clearance.
Less is better as long as it dont rub the housing.

 

[Big T]

I ordered a new fan for $17. Shipped it to Montana where it will come down with my wife end of next week.

 

[dbrannon79]

@Big T measure the diameter on the groves of the pulley, those two looked the same in your photo. the fans should be the same between the CS-130 and the 144 so you could swap them too. and iirc there should have been a spacer on the cs-130 that you can use for it as well.

 

[Big T]

@Big T measure the diameter on the groves of the pulley, those two looked the same in your photo. the fans should be the same between the CS-130 and the 144 so you could swap them too. and iirc there should have been a spacer on the cs-130 that you can use for it as well.

Clearly the pulleys are not the same size in the photo. Furthermore, I know they are not the same size based on how far I had to move the tensioner pulley just to get the belt on.

I have the spacer and it’s on there with the CS-130 fan. The diameter of the CS-130 fan is at least 1/2” smaller than the CS-144 fan.

 

[dbrannon79]

in other news today I have been noticing the AC in the 93 not cooling as well as it has been. even though outside temps are in the mid 80's now.

connected my gauges and it was a little low. added one fresh can of compressed air! first time since getting it working last summer that I have had to add any to the system. it's charged with compressed air aka office duster or known as R152a. after adding a 10oz can the vent temps got down to just a hair over 40 degrees!

looked over the system for any indications of a leak and saw where the front hub on the clutch is a little oily. think the front shaft seal has a slow leak. to be expected as this compressor has been on the truck since before 2009 and sitting open to the atmosphere until I pieced it together and got it working.

iirc I think the front seal is available if I want to try and replace it. I may look at that after the winter season, possibly pull it and rebuild it if I can.

I have the old compressor I took off the 95 I can tear apart as a practice patient LOL