Shifting hard?

I have recently changed spark plugs, oiled everything on driveshaft, I get my oil changed every 3k miles. I have 142xxx miles on the truck but lately it seems as if its just shifting hard. When im at red lights and have my foot on the brake as soon as i take my foot off it jerks. Has anyone ever had this issue?

 

Are you sure it's not axle wrap? You're not shifting as soon as you let off the brake.

Is it more of a soft "clunk" or thump?

 

It's just more of a thump. It doesn't make any noises just jerks. And it could very well be axle wrap. What are signs of that?

 

A thump......

Sorry, had to say it.

It's hard to say....but chances are, it could be axle wrap, or driveline slop, or it could be normal transmission thump.

With truck in park, and transmission in Park.... Crawl underneath and grab the rear driveshaft. Rotate it.... How much play is there? The more play there is, the more slop you have and this can give you a thump.

Axle wrap has to do with the suspension being under load while you're on the brakes....and 'coming to rest' when you get off the brakes. This will depend on how fast you came to a stop (more or less - while trying to explain it).

Transmission thump.... is something even 2nd gen trucks get..... but normally you'll feel the clunk after you've come to a complete stop with foot still on the brakes. It's a 'late' downshift (more or less). Again, the harder / faster you come to a stop....the more often (or harder) the clunk will be.

 

No its more of when im at a stop and go to take my foot off the brake to go again. and sometimes when im just normally driving and its shifts gears. I will look at the driveshaft when i get a chance. Thanks. And also my lift in the rear is a 2 inch block. How would i know if i have axle wrap for sure or not?

 

You're gonna get a lot more axle wrap with a 2" block installed than you would without them.

Here's a video... Just to show you how the suspension can flex .
http://m.youtube.com/#/watch?v=cMw7KVvisv8&desktop_uri=/watch?v=cMw7KVvisv8

 

I believe I'm having this same problem. I don't have blocks in the back and don't seem to have any sagging. I saw they make helper springs. Got an amateur question here, but if it's transmission thump, how big of trouble is that to fix?

 

I just got under my truck, the front driveshaft does have some play in it and where it connects to the transmission it clicked when i twisted it. It did have some play in it. How would i know if i for sure have axle wrap?

 

Probably have to get a new transmission. That would be my guess but maybe somebody that knows could tell you.

 

When you say "shifting hard" do you mean just the axle wrap "thunk" or is it shifting hard thru out the shift points ??

 

When was the last time you had the transmission serviced /oil Change /flush?

 

Bingo !! This is where i was going... OP if you haven't serviced your trans I emplore you to do so ASAP !! I had just a couple of unusually hard upshifts the night before my trans had a major melt down & trust me you don't want to spend the $$$$ for rebuild (I was quoted up to $3400.00, thats $1.00 per cubic cc..)

 

hey im rebuilding my trans now, i will pay no where near that much to have it done. even if my labor hours were 100 per hour.

 

Well then you'll save a shitload of $$$$....... notsure

 

I bought the truck with 123xxx miles and it has 142xxx now. From the time i have had it i havent done it. And i dont know if it got changed before me or not. But also my dad thinks by it having this many miles it could be bad to change the transmission fluid. Ive heard several people say that?

 

How can i tell if it needs to be changed?

 

and its right when its upshifting. depending on where my rpms are at. Sometimes it doesnt shift hard and sometimes it does. But only when it up shifts i believe

 

Well... It could be bad if you don't change it.
Does it have a transmission dipstick? Take a look at it. What's the oil look like or smell like? Is there enough oil?

Also, have you checked for any diagnostic codes? Even though the CEL isn't on, doesn't necessarily mean there aren't any codes stored on the computer. There are critical sensors that, if failing, can cause the tranny to shift inconsistantly.

 

The trans flush is a regular maintenance thing & I've had auto trans before that I NEVER flushed & never had a problem, but for whatever reason these A340F (if 4wd) really require the maint. & I wouldn't put it off AT ALL !! I did & mine smoked seemingly over night, nothing dramatic it just quit...& upon inspection I dropped the pan & there was like half a pound of metal

 

You can check it by pulling your transmission fluid dipstick out. It's the orange one to the left of your block.

If the fluid is brownish-black, you've burnt your transmission fluid, which is very bad.

If it's a vibrant red, then you're a-okay!

Check it while your truck is running, unlike engine oil.