[Dakmm]

If I buy a pump that comes with the pulley, does it matter if I buy a 17mm or 18mm?

I have the 4.7 in my truck, and I've heard I could have either size in there, but I want to order the part before I start the job, not wait until I get the old pump out to see which one is on there.

Thanks.

 

[Dakmm]

C'mon somebody must have an idea of this? I know if I was planning on re-using my pulley I would have to get the pump with the same size shaft, but if the pump comes with the pulley will the shaft size matter?

Will both the 17mm and 18mm pumps bolt up the same to a 4.7?

 

[MONKYMAN]

I personally don't know about the 4.7. On my truck the only thing I have an option of is a new pump with or without the reservoir.

Is this 17 or 18mm you are talking about the center splined pump shaft?

 

[Dakmm]

I'm not sure, all I know is when I went to get a price they told me it could be either a 17 or 18mm shaft, which is what I've seen a bunch of people ask when I searched, but didn't see any answers.

If it's just a shaft outside diameter difference I don't care as ling as it bolts in the same. If the pulley itself is a different size diameter then that's a problem. But if the pulley is the same size and it's just a different size shaft, it seems like either will work.

Thanks.

 

[MONKYMAN]

Humm that's weird. Order one that comes with a pulley if you can. 17mm is around a half inch. so that is for sure the pump shaft. Can you get it in town like AutoZone or some place? You could compare them both and then decide which you have.

 

[Dakmm]

Yeah I can get it at the NAPA by me, but it's $180. Rock Auto has one for $80. Both come with the pulley.

When it comes down to it, I really don't care what size the shaft is, as long as it will bolt on and work. Just want to make sure the bigger shaft doesn't also have a slightly bigger pulley so that once I'm all done my belt won't go on. I guess I could measure the radius of the pulley on my pump and then go to NAPA and measure that pulley.

I'd much rather get the one from rock auto that is $100 cheaper, but it may be more of a hassle than it's worth if it isn't right.

 

[mikeglass1969]

If in doubt call Rockauto, they are very helpful in these situations. They will actually send someone out on the floor and physically check and measure.

I personally had them check on wheel hub and bearings. Not picture was given and I needed to know if the ABS sensor wire was included. Sure enough, the sent someone out.

Give it shot...

 

[Dakmm]

Cool thanks, I'll give them a call.

 

[trad444]

Pump is the same and will bolt up. Not sure why the 1mm difference in shafts.