vx is shifting badly

[stu]

I bought a vx in november of last year and love the vehicle but I changed the oil in it last week and for some reason, right after that it started to shift very rough and seems to be sliping in gears. Does anybody have any good ideas as to what this might be?

[mbeach]

Did you change the oil yourself, or did you take it in to have it done?

If you took it in, there is a very real possibility that you are now low on transmission fluid. The 4L30E transmission is a sealed unit -there is no dipstick to check the fluid level. On the bottom of the pan, there are two plugs -the lower for drainage, and the higher for fill/check.
It is possible that the pit jockey either pulled the wrong plug to check the level, or they let fluid out when checking the level from the top plug (easy to do when the engine is running).

The transmission is a decent unit, it just requires above average attention to detail on the part of the service department. It is not Isuzu specific, as it's a GM model, and found in many vehicles.
I'd recommend that you take it in for a transmission service -somewhere that knows for certain how to check and fill a sealed transmission.

[Ldub]

mbeach,
Would you outline the proper procedure for checking the tranny fluid level?, I was under the impression that it was checked by removing the top plug while idling, in park, with the trans. @ warm (operating) temp.
I'm pretty sure I've seen this info. posted before, but thought checking again wouldn't hurt.
Thanks, Ldub

[mbeach]

Joe Black does the best job of explaining the service here:
http://www.antiquecaterpillar.org/vx...l/4L30E_01.asp

The service CD has another procedure for checking fluid, and it's not likely to be known by the average Jiffy mechanic.

1.) Park vehicle on level ground, apply parking brake.
2.) Check fluid level with engine running at idle
NOTE: Ensure transmission fluid temperature is BELOW 86*F
3.) shift through all gear ranges
4.) shift into park
5.) idle for 3 minutes, then open the overfill screw(the top one).
6.) add fluid until it flows out of the opening
7.) let engine idle until a fluid temp. between 90*F and 135*F is reached, THEN close the overfill screw. Fluid temp is checked with a scan tool.
8.) torque screw to 28 lb ft.

Minimum fluid level @135*F
Maximum fluid level @ 90*F

DO NOT:
-open the overfill screw with the engine stopped
-immediately after driving at sustained highway speeds
-in city traffic, during hot weather
The vehicle should be allowed to "cool" for 30 minutes if any of these conditions are present.

I should have made my earlier post clearer -it's easy to assume that the fluid level is full when then engine is off. Most people (myself included) are not too keen on sticking their finger into a fill hole when the engine is running.
If the engine is hot, they could've figured that it was low on fluid then added some to bring the level up -overfilling it. This would cause driveability issues as well.

[Ldub]

Thanks,
I was thinking I'd been doing it completely wrong...at least I was in the ballpark. Now, to fine-tune.

[IndianaVX]

so is the "sticking finger in hole" operation to check level, temperature, or type of metal certain round body parts are made of ?? I would assume that full would mean that as you fill, fluid would run out, and then stop when it can no longer "run" over the lowest edge of the hole,now its full,- correct??? also, i dont have a scan tool, so will my moms candy thermometer, (or equivilant,) work...not sticking the thermometer in there, sticking the turkey baster in there (or syphon) to get some fluid out,put fluid in jar, and check temp. or can you drive a half mile to get to check temp, or will tran fluid warm up along with engine temp. i have to change tran fluid, and would like to do it myself, in two changes. so i want to be doing this right. have read the other post on this also.
thanks in advance
david

[mbeach]

I generally check diff fluid level with my finger -the transmission fluid could be at any level below the hole -especially if the trans is warm. I've jammed my pinky in there, just to see if I could feel fluid. This is not the way to do it, but I tried it anyways. The correct way to check the level on the transmission is to open it up and add fluid until it runs out.
I don't see your average mechanic at Jiffy Lube just "throwing fluid away" to see if the transmission is full or not. They'd open up a hot tranny, and since no fluid came out, they would assume that it was full. After all, the truck is running.
I have a cool pyrometer at work -it's like a little temp sensing gun. It's come in handy for about a dozen jobs around the truck. I'd like to get one, they run about $150. I'll be that it would do a fine job of checking the temperature of the transmission pan.

[stu]

No I changed the oil myself and did nothing to the transmision fluid. I Just checked it yestarday and noticed that it looked like it had a lot of metallic color to it which to me does not seem to be a good sign. However I did not check it the way you are suppose to I just opened it up and some came running out the engine was not on. It seems to be engaging and disengaging like the transmision is confused or something. I checked the tire pressure and it was way low. Filled them up to 50psi. but still have same problem. Not sure what else to do. Really do not want to take it to a shop if it is something I can do myself. The VX has about 72000 miles right now and not sure if it needs to have trans fluid changed I have only had the vx for the past 6000 miles or so.

[WyldWeasel]

I took mine into the local Oil & Lube place the day I bought it. The idiot pit jockey's put Mobil One oil instead of ATF into the transfer case. Luckily they refused to service the tranny because it didnt have a dipstick and I took it to the dealer the next day for a flush and they discovered the issue and flushed the transfer case and refilled it with ATF.

Also, if your tranny seems to not know what gear to be in, it might need a mode selector switch. Do a search of the forum for that info, it seems to be a common problem that crops up when tranny's act up.

[Ldub]

I knew I'd seen this kickin' around somewhere & here it is.
I know it's redundant, but may be of some help.

[WyldWeasel]

As I said back in Moab, you rawk, Ldub!

[Ldub]

I can't take any credit for that...someone else posted it, I just habitually save every bit of useful info. that I see & keep it for future reference...IF I can find it. Truth is, I got lucky this time, but thanks.

[Ldub]

bumpage 4 the new guy (mr.allcaps?)

[VCAMILO]

Note: Be sure the transmission fluid temperature is below 86F.

LOL! What about the folks that live in Phoenix? Its 110 everyday. LOL!

Thanks everyone!

[Ldub]

Note: Be sure the transmission fluid temperature is below 86F.

LOL! What about the folks that live in Phoenix? Its 110 everyday. LOL!

Thanks everyone!

Dude,
Ya gotta check it a 3 am... at least It'll be a little closer to 86.