1996 Grand Cherokee transmission rebuild & on to other stuff

[DoubleDingo]

I hate going back in and doing work more than once. I feel your pain. At least you found the problem and have a "new" controller. You can always have your old one redone and keep it as a backup.

 

[SirRobyn0]

I hate going back in and doing work more than once. I feel your pain. At least you found the problem and have a "new" controller. You can always have your old one redone and keep it as a backup.

That's actually a really good idea, after the summer is over the fall bird sales for Thanksgiving I might just use a little of the money to send my old one in to be rebuilt.

Well walking by the Jeep going from one farm thing to the next I thought I'd take 15 minutes to see what I could find. Sure enough hidden from view by the carpeting a large gauge black wire is trapped by behind the heater box grr. Took my large wrecking bar put behind the box and put as much pressure on it as I dare while working the wire back and fourth trying to get it to come free. No luck double grr. Really I'm just glad to know what the solve will be, I hate not knowing what is wrong even more than I do having to do a job over again. It's just a spade connector, I'm about half tempted to cut it, and leave the stuck piece back there, but the mechanic in me tells me that's not the right way to do it and I wouldn't do that to a customers car, while the farmer in me says it's just a spade connector save yourself the time and just get it done.

IDK, it might depend on how time goes tomorrow morning.

 

[SirRobyn0]

She's done!!!!!

So this morning I decided to try one more time to pop the wires out from behind the box, so I stuck my bar in there, pushed down and pulled the wires out!

Hooked them up, the controller lit up, the fan motor came on woo hoo!

From there it was just finishing up the job, getting the glove box and right side covers back on, getting the wires tucked up properly, and recharging the A/C. Next week if I have time I'll suck and fill it at work just to make sure I've got the correct amount of refrigerant in it.

 

[SirRobyn0]

Well because of having to haul hay for the farm last minute last week, I only drove the Jeep the one day, I did nothing to it and it was to cool to get a good test on the A/C system.

So I drove it today.

I've long wanted to get rid of the standard duty fan clutch that I put on it in pinch a few years ago, so I installed a severe duty unit and evac & recharged the system properly. I was only about 1.5oz off in my guess. But here is what happened on the way home tonight.

This is what the Jeep was reading:

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The official temp was 90F at the time.
This was the vent temp on the road.

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She'd creep up to 50F at idle, which is a little warmer than ideal, but even still that's a 40 degree temp change, so I feel that's very good for an old Jeep I might try cleaning the condenser if it seems problematic but it seemed to keep me comfortable on the ride home so I'm good with it!

 

[DoubleDingo]

Not bad at all

 

[squaredeal91]

Looks cold to me, I haven't gotten our 99 suburban to blow any colder than that lol

 

[SirRobyn0]

@DoubleDingo & @squaredeal91 Thanks for the confirmation. They tell us to look for 35 - 40F vent temps and then turn around and tell us 30 - 40 degree temp change is about all we can expect from R-134A, a little less in a retro fit. The Jeep is a factory R-134A. So at 94F that's 45 degree change so that would be considered pretty darn good I guess. I hadn't thought about it like that, I was running recirc, so that might have made the numbers a little better. Anyhow it kept me comfortable on the ride home. AND it held the charge from previously so that's a win in my book!

 

[SirRobyn0]

Ok it sucks today. We have been having record heat hitting the mid-90's officially though I've been getting readings just shy of 100F both at the shop and the farm. I've driven my retro fitted 84 C20 all week and the truck has had no issues keeping me cool. The Jeep not so much. I drove the Jeep today and on my lunch driving it for 45 minutes, the best I could get was 52F vent temps, going down the road 60F at stop lights. Not cool with the sun beating down on me.

I did try cleaning the evaporator at one point. I will pull the grill and have another look at that this afternoon. I'll probably pull the refrigerant out to make sure I haven't lost any but I doubt that's the issue. Fan clutch is severe duty model and was running nearly all of my drive this afternoon so I'm confident in that. I might install a manual coolant to heater box valve to ensure I'm not getting heat leakage into the air flow that way.

I will report my findings and success or failure, but open to advice as well. Thanks.

 

[DoubleDingo]

Ok it sucks today. We have been having record heat hitting the mid-90's officially though I've been getting readings just shy of 100F both at the shop and the farm. I've driven my retro fitted 84 C20 all week and the truck has had no issues keeping me cool. The Jeep not so much. I drove the Jeep today and on my lunch driving it for 45 minutes, the best I could get was 52F vent temps, going down the road 60F at stop lights. Not cool with the sun beating down on me.

I did try cleaning the evaporator at one point. I will pull the grill and have another look at that this afternoon. I'll probably pull the refrigerant out to make sure I haven't lost any but I doubt that's the issue. Fan clutch is severe duty model and was running nearly all of my drive this afternoon so I'm confident in that. I might install a manual coolant to heater box valve to ensure I'm not getting heat leakage into the air flow that way.

I will report my findings and success or failure, but open to advice as well. Thanks.

Non working a/c bad. I say that and mine doesn't work...lol... But it wouldn't cool me down in the 15 minutes to get home anyhow...lol...

 

[SirRobyn0]

Non working a/c bad. I say that and mine doesn't work...lol... But it wouldn't cool me down in the 15 minutes to get home anyhow...lol...

There is a road closed for 6 weeks between the shop and the farm whilst they replace a culvert, my drive is currently an hour and half.... It does work and it is better than nothing. I'm sure left on recirc after about 45 minutes it would be ok, but yea I'm not having this at all!

 

[Bextreme04]

Ok it sucks today. We have been having record heat hitting the mid-90's officially though I've been getting readings just shy of 100F both at the shop and the farm. I've driven my retro fitted 84 C20 all week and the truck has had no issues keeping me cool. The Jeep not so much. I drove the Jeep today and on my lunch driving it for 45 minutes, the best I could get was 52F vent temps, going down the road 60F at stop lights. Not cool with the sun beating down on me.

I did try cleaning the evaporator at one point. I will pull the grill and have another look at that this afternoon. I'll probably pull the refrigerant out to make sure I haven't lost any but I doubt that's the issue. Fan clutch is severe duty model and was running nearly all of my drive this afternoon so I'm confident in that. I might install a manual coolant to heater box valve to ensure I'm not getting heat leakage into the air flow that way.

I will report my findings and success or failure, but open to advice as well. Thanks.

I've been driving the square in this all week and the AC has been on point. I have a GMT-400 mirror installed with a temp sensor out in front of the grill and it's been 104 or more down here all week.

Pop the hood and look at your AC return line back to the compressor. Is it condensing liquid or freezing the condensate on the line at the firewall exit? If it is... then your actual refrigerant level isn't the issue. You are either not getting enough airflow through the evaporator, or the heater core is heating the air up(either through a blend door issue or a heater flow valve failing). You can always just put in a ball valve and physically shut off the heater core flow when you want it to be the absolute coldest it can possibly be.

 

[SirRobyn0]

I've been driving the square in this all week and the AC has been on point. I have a GMT-400 mirror installed with a temp sensor out in front of the grill and it's been 104 or more down here all week.

Pop the hood and look at your AC return line back to the compressor. Is it condensing liquid or freezing the condensate on the line at the firewall exit? If it is... then your actual refrigerant level isn't the issue. You are either not getting enough airflow through the evaporator, or the heater core is heating the air up(either through a blend door issue or a heater flow valve failing). You can always just put in a ball valve and physically shut off the heater core flow when you want it to be the absolute coldest it can possibly be.

It is condensing liquid and that was my thought too that refrigerant level is likely ok, I just figured the machine could do a suck and fill to verify while I did the condenser clean. I just replaced the evaporator, and heater core so we should be good there. I went ahead and ordered a manual shut off valve for the coolant in the heater hose but. I better call the suppler.... On hold not looking good for seeing it tonight..... Nope won't see it until tomorrow morning. Soooo. I'm going to follow though with giving the condenser another good look at, seeing if there is dirt or pine needles I missed from last time and then finally seeing if the all the air scoops are there like they should be. Maybe I'll see if I have a hose pincher and try pinching off the inlet line to the heater core, they are new hoses so they should be able to handle that just fine.

 

[SirRobyn0]

Sorry about the late update I got kind of side tracked after getting to the farm. Gotta cook dinner, put the birds away and then I spent almost an hour just sitting on the couch with Misty (our dog).

Ok here is my after work update / progress. So I took the grill and top support for the radiator off. The edge seals for the radiator to condenser are there. There is no bottom seal but there is the bottom core support and it seems pretty tight so I think that's okish. The top is wide open for air to go though the top 3 or 4 inches of the radiator and not though the condenser. Despite an earlier in the year cleaning of the condenser fins it still looks pretty terrible especially between the transmission cooler and the condenser. So I did another degreaser cleaning and tried to get as many evergreen needles out of it as possible. Ultimately I'm either going to need to find a way to clean it up really good or replace it, but I improved it. Then I stuck a piece of pipe insulation between the radiator and condenser top and ran a strip of tape across the top. Picture:

Before:

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After:

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It probably should have some kind of plastic flap there and my home brew thing cuts off some air flow to the top of the radiator which of course is not ideal, but will work for now.

Then I used a hose crimp tool to crimp the inlet hose to the heater core.

My drive home:

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First bit is getting on the highway and sitting in traffic. It's only one exit but took 15 minutes to get that far today. I saw steady vent temps of about 50F, or just a hair above. As soon as I got out of traffic and was moving I was seeing almost 45F at the vents. That's about 50 degrees less than outside! I'm good with that! Getting into the valley driving along the Snoqualmie river the outside temp dropped to 94F and I was seeing vent temps of around 40F! I had to get out in Fall City and I left the Jeep running for a few minutes, when I got back the vent temps were still below 50F of course at that point the air was pre-cooled in the Jeep and I'd be running recirc. So I feel like the results were excellent, certainly I was much more comfortable on the drive home than I was at lunch. I need to either figure a way to clean and remove all the evergreen needles from the condenser or replace it, and make a proper to shield / gasket. I'll have a valve to install in the heater hose tomorrow and will install it over the weekend.

I'll report back on how that all goes. It's suppose to remain hot next week, but not quite as extreme (mid & upper 80's), hopefully I'll get to drive the Jeep a few days then as well to see how it goes.

 

[DoubleDingo]

One tip I will share, is to add a piece of metal window screen with the edges folded over to give it a little strength and allows it to fit between/behind the grille. After I got my Jeep I was doing a lot of back and forth driving for visitation, and a few times I encountered bees, and bees plug up radiators and condensers in a hurry. After spending a couple of hours picking out debris and insect pieces, I installed some of the screen as a safety feature to catch insects before they get into the fins. It works well, and I have not had to clean the fins for almost 20 years now.

 

[SirRobyn0]

One tip I will share, is to add a piece of metal window screen with the edges folded over to give it a little strength and allows it to fit between/behind the grille. After I got my Jeep I was doing a lot of back and forth driving for visitation, and a few times I encountered bees, and bees plug up radiators and condensers in a hurry. After spending a couple of hours picking out debris and insect pieces, I installed some of the screen as a safety feature to catch insects before they get into the fins. It works well, and I have not had to clean the fins for almost 20 years now.

I gonna do this. Might do it to all my rigs. How did you keep it in place on the grill?