Backhoe 2375 Back Hoe - Grease zerks SAE or Metric?

[exohomestead]

I have the 2375 back hoe with my GC2310. Some of the pivot bars are rusty so I tried greasing them through the grease zerks. Turns out several of the zerks are goobied solid with dried dirt or grease or something. So..

I pulled out a few of the zerks with a socket. Does anybody have hard evidence that the grease zerks are are metric or SAE threads/sizes? I got tricked once before with brake line nuts on a 1989 Dodge Van (one would assume SAE) that had been after-market repaired with newer metric sizes. Getting it wrong caused all sorts of leaks and thread strips down the road. I'd like to get this right without guessing!

If I can't figure out the answer, maybe I'll try putting the goobied ones in an ultrasonic cleaner with a little baby food jar of gasoline, and if they work fine, I'll put them back in the tractor.

~ EH

 

[ray66v]

The grease zerks are metric.

I know because I own one.

Sometimes they need to be replaced.

Sometimes they will take grease, if you move the hydraulics to a different position.

 

[exohomestead]

Ray66v,

Thank you for your reply. I think I'll go buy a pack of metrics. Do you know which size, off hand?

For the two I pulled, I didn't have time to stop by the store today. The insides of the two grease zerks I pulled were full of crusty grease or dirt (couldn't tell which). These were the two closest to the bucket, so maybe they had been packed with dirt during use.

In any case, I picked at the thread side with a pin and found a small pin punch that depressed the spring ball on the other end. I soaked them in gasoline, poked, picked, prodded, put them in an ultrasonic cleaner. Eventually, they were clean and looked almost new! I screwed the same ones back in the hole and they worked great.

One other zerk on the back hoe was a bit sticky, but the grease gun eventually "broke through" and squirted in some grease.

 

[exohomestead]

ray66v,

Did you see the metric designation in a parts manual, or did you simply do the trial and error and found they fit? So far comparing to on-line searches and using my micrometer, the best match I have *visually* is to a Granger 5/16-24 with UNF threads. But I think 5/16 is grossly the wrong size.

My threads measure 0.240", the hex nut is 0.311" and the overall length is 0.541". Can't find a numerical match yet.

 

[MFRED]

Grease zerks on the backhoe and loader are sae. A mix of 1/4" and 5/16" I think. The tractor itself would be a metric zerk.

 

[exohomestead]

MFRED,

Good distinction! Tractor v. attachments. Yes, I'm doing attachments.

I visited a local O'Reilly parts store and they had an entire string of "zerk thread testers". I fiddled around and eventually figured out that it was not 6mm or 8mm and not 1/4" NPT. It was, in fact, 1/4-28, so I bought a pack of matching zerks. I'll know this weekend if everything goes together well.

I'm a little skittish because I had a lot of trouble with a 1989 Dodge Van that had a mix of SAE and Metric on the brake lines. I think it was 10mm, which has 25.4 tpi and maybe 1/4" which had 24 tpi. I'm doing those numbers out of memory, but they were ~very~ close fits. So now I'm careful when they're close in size.

Now, on to decisions of moly lithium grease or just Lucas green polyurea grease..