Zf8 speed transmission slipping?

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Eli Fernandez

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So truck is 2016 91k miles stock no tuner. I was ripping around the other day and I floored it. Shifted from 5th to 3rd when it did i heard a loud pop or crack. After that i feel like it slips but only at 3k rpms in 3rd, 4th and 5th I'll put it in manual mode. Now I know for sure that I have a bad fuel pump. I'm changing that out next week. Would that have anything to do with the truck not accelerating past 3k rpms. It feels like slippage but the weird thing is it wont do it all the time. Some times the truck feels sluggish and other times its perky as hell and just wants to go. Trans temps dont effect it. It'll do it at around 100 degrees and it's done it warm at operating temps. Anyways any help is much appreciated
 

chrisbh17

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Bad fuel pump I would think could cause bogging, engine "dying" under loads, etc. That could feel like the trans slipping, I bet. Especially at higher RPM where the engines fuel needs increase.

I would replace the pump and take it from there.

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Eli Fernandez

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I wouldn't even think the trans was the problem if I hadn't heard that noise at the exact time the truck was at wot and shifting gears. But yes I guess once I get the new fuel pump in I'll see if it's still acting up. This will be the 2nd pump I put in. I've been getting cheap ones online and they've all been bad. I just didnt want to spend $400-600 on a freaking gas fuel pump at napa or auto zone. At least I'm doing the work my self
 

crash68

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A fuel pump that faltering can feel like a transmission "slipping", this happened to a buddy's Suburban.
 
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Eli Fernandez

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I hope so! The dealer wanted 19k for the truck. I ended up getting it for right at 16k bc of the bad fuel pump, the fuel gauge didnt work and the new pump I just put in whines like crazy and I have to turn key like 3 times for it to start without sputtering. I didnt get the stupid rip-off extended warranty. It would have added another 5k to the price.
 

Wild one

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I hope so! The dealer wanted 19k for the truck. I ended up getting it for right at 16k bc of the bad fuel pump, the fuel gauge didnt work and the new pump I just put in whines like crazy and I have to turn key like 3 times for it to start without sputtering. I didnt get the stupid rip-off extended warranty. It would have added another 5k to the price.

Bite the bullet and buy a factory OEM pump.There's lots of horror stories of the aftermarket pumps causing a lot of issues
 
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Eli Fernandez

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Well that's the thing I've heard that the factory mopar pumps still haven't got an updated floater and it could be hit or miss with them. And they're like $600 bucks. The autozone ones are like $300. I do the work myself so that's not another cost thankfully. The pump I got was way too cheap also it was $89 from 1Aauto. This is the first and last time I'll ever cheap out on parts for my truck lol...
 

Burla

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If you keep going through fuel pumps you could have an intermittent short to ground. If it happens again, just re-wire that as well.
 
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Eli Fernandez

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I bypassed the TIPM with a premade 20amp cable and it didnt make a difference but I'll check the grounds on it!
 

cwendel

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Just order the pump from Rock Auto. You should be able to get the factory assembly for less than the dealer.

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