Sunday, February 23, 2020

Kick Down! Fixing the TH400 shifting issues

It seems that the PO did some deletions to the transmission to get rid of the kick-down feature on the RV. Not sure why except some think that it's annoying when you floor the pedal and then the RV shifts down a gear (and on a 3 speed that can be somewhat disconcerting!). When climbing hills or trying to pass something (also up a hill) you may need that kick-down option.

Now, this later Chevy has the activation switch near the gas pedal (accelerator) instead of a switch and cable setup found on early Chevy's where the switch was near the carburetor. Basically the idea is that once you floor the go pedal, a switch is flipped that allows for activation of a solenoid in the transmission to shift down one gear for the time you have the pedal depressed that far.

I looked under the dashboard to see what I had near the accelerator and there was that GM kick-down switch! I pushed the pedal down as far as I could with my hand and could not activate that switch. It would take considerable pressure on the pedal by my foot to get that switch to move! First issue found. The other one is making sure the wiring is hooked up to that part of the transmission to allow the voltage to activate the solenoid. Have not checked that yet but I recall a wire hanging loose near there.

This is the Allegro's setup with the switch set in a way that you have to REALLY punch the gas to get it to move. Purple wire is 12V source and orange goes to the shift terminal on the TH400. 

Stock photo showing a shiny plug in the place of the terminal lead to activate the shift solenoid that's accessed by dropping the transmission pan. Hope that part is still there and working!!!
Here are pics of the gas pedal switch, wires and a stock photo showing where the plug should be on the transmission. This plug photo works better showing the location than almost any one with the terminal lead on the dirty and grimy transmissions.

I'll update this once I get the connections adjusted, including putting a section of hose around the switch post to get it to activate a bit sooner... tip I found on-line!

Thursday, February 20, 2020

The RV Laundry List: What do you fix on your RV?

The last Road Trip to Myrtle Beach (a 1600 mile round trip, by the way) helped sort out some issues on the RV. Some of which are:

1) Vibration due to tire noise and imbalance.
2) Removal of washer hoses for wipers by PO
3) Running the 454 engine at 3K+ for the trip to keep at highway speeds.

Those are the major issues we encountered on our last trip. The first one is going to be mitigated by a company called Centramatic. This company builds dynamic balancing rings that fit on the tire hubs and counteract the imbalance of the tires at all times.

Their website can be found here:
I bought two sets, one for the front steering wheels and one for the drive wheels. We shall see how it improves the ride. Any reduction in vibration during our trips will be welcome.

The second issue will have to be dealt with by getting new hoses and nozzles for the wipers. The pump and tank are sitting under the hood, awaiting reconnection. Based on the this last trip with the salt and spray build-up on the windshield, I can't wait for a fix.

The last issue has been a matter of debate. Do you pay 3K for a Gear Vendors unit to get you overdrive and some mid gears you don't really need? Do you pay 2K for an R700 4 speed tranny to get overdrive and different gears for the shifts? Or, do you decide to get new rear end gears without disturbing RV owners and have a shop slip in the new 3.73 gears to replace the 4.10 ones you have now and drop  cruising rpm by 300-400 rpm?
This may require both. I've ordered the dynamic balancers and am working on a shop that will do the read end swap. Stay tuned!

Tuesday, February 11, 2020

Wintertime RV tasks

It's winter for all intents and purposes here in Western NY. For RV's that means checking out systems, keeping batteries topped up and making sure that all the things that work in above-freezing temps are protected for the next camping season.

Check out my UTube channel for all the latest videos of me attempting to keep the rig in good shape while working 2 jobs.

Here: The Vintage RV'er Channel

After a close call with the better-half deciding that it would be best to sell the Long Hauler, we've decided to plan some extra trips with the kids and really just kick back and enjoy the experience (okay, the "experience" has been mechanical break-downs, leaving the last RV in Floriday and driving back in a rented van....)  so we have come PTSD issues to work out each time we head out on the road.

The next trip is back to one of our old stomping grounds during the ill-fated road trip with the LH1. Myrtle Beach.

Here's the map:
2020 Trip Map to Myrtle Beach

I'm checking off items on my to-do list such as re-clamping the sway bar link (done!), changing the oil (will do tomorrow am....) and other stuff to make sure the experience is as drama-free as possible.

Good night all! Happy and Safe RV'ing!