Is the transfer case fluid completely separate from transmission fluid on 91 Chevy K1500? Also, what is the size of the filler & drain plug on the transfer case

Hi everyone,
Is the transfer case fluid completely separate from the Automatic Transmission fluid on a 91 Chevy K1500 ? This is the transmission with
16 bolts on the transmission oil pan (I think the 4L60 model).
I have a small leak at the rear seal on the output shaft of the transfer case (where rear drive shaft meets the transfer case) but I'm also due for an automatic transmission fluid change. I want to change the automatic transmission fluid first and then replace the transfer case seal later when I have more time. It's not a real bad seal leak, there's nothing in the driveway, a couple of good size drops of transfer case fluid (ATF fluid) is always hanging at the bottom of the seal and/or housing. If the fluids are completely separate, then it will be no problem to change the ATF fluid first.
Also, does anyone know what size wrench that the filler and drain plugs take on the transfer case ? I wanted to check the transfer case fluid level, but don't have a wrench that is quite big enough. It measures 30 mm across the flats with dial calipers but I don't know if its metric or inch. If not metric, then it must be a 1-3/16". I put on an adjustable wrench, but it felt like it was going to deform the flats, so I need to get a wrench to fit.
Thanks for your help. John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Fluid in trans and t-case are separate, no problem there, As to the size, you already answered your own question. Without those sizes, sometimes a 1 1/4 6 point will work. Get a 30mm deep, they fit a lot of things, like axle nuts on some fwd cars.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks Kevin,
Kevin wrote:

John: Well, I came close to answering my own question on the size of plugs. I won't really know if its inch or metric until I get a wrench on it. I don't want to buy two wrenches, so unless the store will let me try both before buying, I need to find out which one it is. I was hoping someone here might know for sure.
Thanks again, John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

drain plug size = believe your tools! 30mm..you measured it... but, i use a one and a quarter 6 point that is a little sloppy but works just fine as it does on axle nuts and many other metric apps..........for the money spending rich folks, buy every tool you can. it helps the tool man and the economy in general!...for those of us that like saving money, improvise! i dont recommend using 13mm on 1/2 inch or 5/8 on 15mm but when you get to large hex's and use 6 points their are a lot of metric/sae swaps that work fine....IMHO.....kjun
--
The Source For Premium Newsgroup Access
Great Speed, Great Retention
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hi Kjun,
Thanks for your message.
Kjun wrote:

John: It was actually 30.1 mm which is 1.850", & that's only .006" larger than 1-27/32". Now, take into acount manufacturing tolerances and the fact that there is play between the wrench and the nut flats, and I thought it could go either way. I guess it's metric, but the truck use both metric and inch.
I will try to pick up a cheap 30 mm wrench somewhere since I only need it to check the transfer case fluid every now and then. Perhaps they will let me walk out and try it just to make sure. The bigger wrenches are expensive.
Thanks again, John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Why not use this as an opportunity to expand your tool collection? (G) A set of large sockets for wrenches is a nice addition. If you are just a shade tree, perhaps a import set like Harbor Freight will suit you. I got a really nice set of impact duty 1/2" drive sockets that goes up pretty high, but I doubt it goes to 30mm, however there are other sets. As previously stated, on larger sizes there are some metrics that equal SAE sizes, in fact my set from HF has some sockets that are good for both as shown in the case. Justify your purchase to the wife by noting the price of having it done at a shop. I've bought many many tools that way, although she did balk at the welder until I built some neat stuff with it.
Also, sounds like your trans rear seal is leaking and the wind is blowing the droplets back onto the transfer case housing, as the transfer case typically takes a much heavier fluid, usually black in color, but yours might be different.
D
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
scott wrote:

I seriously doubt you will find a 32nd sized wrench that large (wrenches by 32nds are generally only used for aircraft anyway) so it's probably a safe bet it's 30mm
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for the additional feedback Scott & Nate,

John: Actually, this transfer case uses Automatic Transmsission fluid, which is why I had asked if the fluids were separate. I have now replaced the trasnfer case seal, and that problem is fixed, so one less thing to worry about. It had been getting worse, first on drop every now and then (no big deal) then two, then more and bigger drops, etc.. It was easy to see right where it was coming from.
Scott:

John:
You can't have too many tools, but I've never needed a 30 mm wrench for anything else, so I will probably just buy one for now, unless I find a real good deal on a larger set.
Thanks again, John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber 668
This is one option - although I personally like a longer conventional style, combination wrench this would likely work fine.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.