Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-12-2018, 09:15 AM   #43
2 Rivet Member
 
1987 29' Airstream 290
Los Angeles , California
Join Date: Dec 2016
Posts: 63
Quote:
Originally Posted by Waipio Rim View Post
My transmission doesn’t like to downshift as early as I think it should when going uphill, so I am always shifting in and out of second by hand when the roads get steep. Whenever I go from “D” to “2”, uphill or down, I give it a little gas to bring the rpm’s closer to where the trans wants them to be right when I am making the shift. Kind of the same thing that you would do with a manual transmission, to ease the shock to the clutch and the rest of the drivetrain. That might encourage yours to downshift when you want it to. I’’be been driving mine this way for the last nine years or so, and the trans works just like it did when I got the coach.
Wapio that’s a good idea bringing up the RPMs but if I’m going downhill in D and i hit the gas isn’t it the opposite of what I’m going for? ; But seriously, can I raise the RPMs like this in neutral and switch quickly into 2nd? I’m missing something. I know how to do this on a manual transmission but not yet getting it with the 3-speed automatic.

For other posters, I had the brake lines and fluid replaced after the first...fade? Lock up? The mechanic said there were a lot of air bubbles in the fluid. But no indication of the root cause of the problem. Not sure what type of fluid they put in but if I have the problem again I will switch to Dot4. Hot brakes seems to be the catalyst.
__________________

GinaParmesan is offline   Reply With Quote
Old 02-12-2018, 10:33 AM   #44
Rivet Master
 
Waipio Rim's Avatar

 
1984 31' Airstream310
Honokaa , Hawaii
Join Date: Jun 2010
Posts: 770
Quote:
Originally Posted by GinaParmesan View Post
Wapio thatís a good idea bringing up the RPMs but if Iím going downhill in D and i hit the gas isnít it the opposite of what Iím going for? ; But seriously, can I raise the RPMs like this in neutral and switch quickly into 2nd? Iím missing something. I know how to do this on a manual transmission but not yet getting it with the 3-speed automatic.
I try to get down to 35mph or less one way or another before shifting, and it's just a quick bump of the pedal at about the time I am pulling the lever from D to 2. It may be more of a torque thing than an rpm thing, just a suggestion. After reading what Smartstream posted above, it may not work for you.
__________________

Waipio Rim is offline   Reply With Quote
Old 02-12-2018, 12:37 PM   #45
Rivet Master
 
Mollysdad's Avatar
 
2017 26' Flying Cloud
Tampa , Florida
Join Date: Feb 2017
Posts: 2,731
I can't think of any reason to ride the brakes.
They get red hot. After all they're designed to create friction.
The heat boils the brake fluid, and surprise, no brakes.
Mollysdad is offline   Reply With Quote
Old 02-12-2018, 01:49 PM   #46
1 Rivet Member

 
1976 31' Sovereign
Eagle Point , Oregon
Join Date: Jan 2018
Posts: 13
downhill

As to the original question, please forgive my longish answer. After driving several million accident free miles, a lot of them in 105,000 lb trucks in the mountains of So OR, IMHO no matter what type of vehicle you are driving if you find yourself using the brakes for very much more than the last few feet before coming to a stop, you are either driving too fast or not paying attention to the road ahead or the surrounding traffic. Like many of the others have rightly said use a low enough gear so that you do not need your brakes. I like to ask myself when going down a steep grade, if I round the next curve and traffic is at a dead stop, will I be able to safely stop without crashing/killing/hurting anyone. Those you love that are riding with you and those you may run into are depending on you. Almost all the hills/mountains that are very steep have a warning sign and usually the length of the downgrade. Most of us professional drivers like to get at least halfway down before letting vehicle speed pickup to posted limit. Then if you need to, apply very light steady pressure on the pedal. If you are going too slow down a hill for others they are welcome to pass and like the old fella that taught me to drive in mountains said 'you can only go down a hill once too fast'. If you are in a big hurry either leave sooner or take a faster mode of transportation. Airstreaming is all about having fun and enjoying life. For me the choice on brake application has always been light steady pressure when necessary. We routinely drove in excess of 100,000 miles before changing brake shoes/pads.
__________________
1995 F-250 ExCab Long Bed 7.3 Powerstroke 2WD
Metal Topper w/rack for boat usually full when camping
14 mpg Towing 17-20 Empty
1976 Sovereign 31' CB Rear Twin towed 'on the ball'.
Olscot is offline   Reply With Quote
Old 02-13-2018, 06:57 AM   #47
Rivet Master
 
Keyair's Avatar

 
1984 34.5' Airstream 345
Foothill Ranch , California
Join Date: Mar 2010
Posts: 4,288
Images: 1
Driving downhill: Pump or riding

Gina,
You say when you down shift to L2 the transmission feels like it is in N?
Do the engine revs drop to idle, and there is no engine braking at all?

If so, this is one I know about!
My 1987 Suburban 2500 had the same issue. 454 with Th400.
Itís not a good situation, and you should get this fixed ASAP.

Only figured it out when I stripped the transmission.
One of 2 issues.
1/ 2nd gear friction band is toast. Transmission needs to come out and be rebuilt... or..
2/ Plastic apply piston for the above friction broke. I think this can be done in the vehicle. The plastic part is weak, and gets brittle with age. Center part of it breaks(not Brakes... wink at Tony), and there goes control of the L2. Known and common problem, and itís not a coincidence that your trans is also 1987. Replacements are all aluminum now for good reason!

I will post some pics and more info in a bit!
__________________
My name is Steve.... and I am an Alumaholic!
Working in my Garage is like playing TETRIS with Tools!
Keyair is offline   Reply With Quote
Old 02-13-2018, 09:46 PM   #48
2 Rivet Member
 
1987 29' Airstream 290
Los Angeles , California
Join Date: Dec 2016
Posts: 63
Quote:
Originally Posted by Keyair View Post
Gina,
You say when you down shift to L2 the transmission feels like it is in N?
Do the engine revs drop to idle, and there is no engine braking at all?

If so, this is one I know about!
My 1987 Suburban 2500 had the same issue. 454 with Th400.
Itís not a good situation, and you should get this fixed ASAP.

Only figured it out when I stripped the transmission.
One of 2 issues.
1/ 2nd gear friction band is toast. Transmission needs to come out and be rebuilt... or..
2/ Plastic apply piston for the above friction broke. I think this can be done in the vehicle. The plastic part is weak, and gets brittle with age. Center part of it breaks(not Brakes... wink at Tony), and there goes control of the L2. Known and common problem, and itís not a coincidence that your trans is also 1987. Replacements are all aluminum now for good reason!

I will post some pics and more info in a bit!
Keyair, thanks for the reply! Going into 2nd on flat or uphill terrain is no problem at medium speeds of around 40 mph. 2nd works as expected. Itís only tricky when going downhill...even when slowing to 35. Does that still sound like the issue you described? When downshifting downhill, the revs do indeed drop to neutral and engine braking ceases until its shifted back into D in the downhill circumstances, but I havenít tried slowing to 25 mph yet...done driving for this week, so Iíll test and report next opportunity.
GinaParmesan is offline   Reply With Quote
Old 02-13-2018, 10:01 PM   #49
2 Rivet Member
 
1987 29' Airstream 290
Los Angeles , California
Join Date: Dec 2016
Posts: 63
Quote:
Originally Posted by WayneG View Post
You are almost the shortest Airstream Labeled MH, Mine is a 270, The argosy's go all the way down to 20'.
That said I tend to overload mine (with spare parts & beer) and tow a Trailer with a full size Polaris UTV.
Ah! Is the 270 also on a P30 chassis?

Love that spare parts and beer are getting equal weight in your travel prep. ;
GinaParmesan is offline   Reply With Quote
Old 02-13-2018, 10:37 PM   #50
Rivet Master
 
Keyair's Avatar

 
1984 34.5' Airstream 345
Foothill Ranch , California
Join Date: Mar 2010
Posts: 4,288
Images: 1
Sorry, busy day!

Ok, to clarify, my Suburban seemed to shift up and down in D just fine.
But if you were on a hill and pulled it down into 2 or L2, it was like you just put it in N and the engine revs would drop to idle and off she would go, down the hill like a bat out of hell!

So, the part is called the "2/3 Accumulator Piston", or just Accumulator Piston, and it is in the valve body.

The original GM part was plastic.

The suggested replacement part is aluminum, and is available many places
This is an example... its $3.50!
http://www.transmissionpartsusa.com/...-000046954.htm

Since you can remove the valve body with the transmission in the vehicle, it is my opinion that you can remove it and replace the piston.
But you should ask a reliable Transmission shop!

Here is how my 2/3 plastic piston looked....
Broken in 2, and cracked... this fits in the Valve Body shown, in the larger hole with the center pin... fluid pressure is diverted into the piston chamber pushing it and applying the brake band which holds the transmission in L2...
No piston seal... no pressure, no band application...
Attached Thumbnails
Click image for larger version

Name:	2-3 Acumulator Piston.jpg
Views:	35
Size:	88.5 KB
ID:	304224   Click image for larger version

Name:	2-3 Acumulator Piston1.jpg
Views:	40
Size:	86.1 KB
ID:	304225  

Click image for larger version

Name:	valve body th400.jpg
Views:	53
Size:	215.8 KB
ID:	304226  
__________________
My name is Steve.... and I am an Alumaholic!
Working in my Garage is like playing TETRIS with Tools!
Keyair is offline   Reply With Quote
Old 02-14-2018, 02:21 AM   #51
Rivet Master
 
WayneG's Avatar

 
1984 27' Airstream 270
Scotia , New York
Join Date: Oct 2012
Posts: 985
Quote:
Originally Posted by GinaParmesan View Post
Ah! Is the 270 also on a P30 chassis?

Love that spare parts and beer are getting equal weight in your travel prep. ;
I think all Airstream classic's are on the P30 chassis, Actually P37 is a more accurate ID with variations according to the wheelbase length.
As for the beer vs spare parts weight, 2 reasons;
1st, I go with no alternate vehicle, so I need a weeks worth of supplies in the woods.
2nd, I need a few brews before I dig into the spare parts for repairs, and several after

Back on the downshift topic, I wonder about the plastic piston for 2-3 shifting. I had not planned on working on my tranny any time soon, how common is this failure? Is it a good PM part to buy?
WayneG is offline   Reply With Quote
Old 02-16-2018, 08:40 AM   #52
2 Rivet Member
 
1987 29' Airstream 290
Los Angeles , California
Join Date: Dec 2016
Posts: 63
Quote:
Originally Posted by Keyair View Post
Sorry, busy day!

Ok, to clarify, my Suburban seemed to shift up and down in D just fine.
But if you were on a hill and pulled it down into 2 or L2, it was like you just put it in N and the engine revs would drop to idle and off she would go, down the hill like a bat out of hell!
Thanks very much for the pics & further info, and no worries, Keyair. Still wondering if 2nd gear was totally out of commission all the time (uphill, downhill, flat, slow, fast) on your suburban when that part was broken, or only when trying to go into 2nd while going downhill at or below highway speed?
GinaParmesan is offline   Reply With Quote
Old 02-16-2018, 09:47 AM   #53
Rivet Master
 
Keyair's Avatar

 
1984 34.5' Airstream 345
Foothill Ranch , California
Join Date: Mar 2010
Posts: 4,288
Images: 1
Iím working on the assumption you have a TH475 3 speed! Anything else is different.

It definitely shifted up through the gears normally. Coming down, in D it was harder to say, but I think it went from 3 to 1.
The real obvious issue was moving the selector to L2. It would climb in L2 but no engine braking. Iím not expert enough to know or understand that difference and what happens inside the transmission between those two events.
I do know that if you lost engine braking on L2 the troubleshooters point to that piston OR the brake band that clamps that drum. I assumed because the PO used to tow a large boat with it, the band frictions were toast. Nope. A simple plastic piston.
If I were you, I would do a simple test. Find a deserted road and accelerate to maybe 40 or 50 in D. Then pull the shifter back to L2 and take your foot off the gas. When the road speed is right the trans will be triggered to downshift.
If the engine revs increase, and you feel a braking effect, itís good. If the Motorhome continues along with no obvious engine braking and the Revs drop to idle, you have a problem.

Wayneís question:
This piston is like $5, so cheap enough to buy. However, if your MH trans has ever been rebuilt its likely it was replaced with the aluminum piston as itís a known and Common failure. The other thing is that itís a PITA to replace, and will not really impact the functionality of the MH to get home or to a repair shop if you drive accordingly. I drove my Suburban over 50k miles with this issue!
However, there is a part I do suggest you carry.
There is a plastic gear on the governor that fails.
A Classic owner had this happen and it left him stuck in 1st gear.
The governor is at the back side of the transmission, and the gear is attached to the output shaft, so it reads road speed. This is what tells the transmission when itís ok to upshift and downshift.
I will find a link to the part.
__________________
My name is Steve.... and I am an Alumaholic!
Working in my Garage is like playing TETRIS with Tools!
Keyair is offline   Reply With Quote
Old 02-16-2018, 03:20 PM   #54
Rivet Master
 
Keyair's Avatar

 
1984 34.5' Airstream 345
Foothill Ranch , California
Join Date: Mar 2010
Posts: 4,288
Images: 1
Here is an example the Governor gear repair kit... its $15.
http://www.classictransmissionsoluti...free-shipping/

Here is a pretty good video of the governor assembly and rebuild, which covers issues, and replacement the gear I hear can strip.

__________________
My name is Steve.... and I am an Alumaholic!
Working in my Garage is like playing TETRIS with Tools!
Keyair is offline   Reply With Quote
Old 02-16-2018, 04:41 PM   #55
jcl
Rivet Master
 
Currently Looking...
Vancouver , British Columbia
Join Date: Oct 2012
Posts: 1,369
Quote:
Originally Posted by Keyair View Post
I’m working on the assumption you have a TH475 3 speed! Anything else is different.

It definitely shifted up through the gears normally. Coming down, in D it was harder to say, but I think it went from 3 to 1.
The real obvious issue was moving the selector to L2. It would climb in L2 but no engine braking. I’m not expert enough to know or understand that difference and what happens inside the transmission between those two events.
I am not intimately familiar with that specific transmission, but I believe that the piston operates a friction band that holds the Sprag clutch. A Sprag clutch is a one way clutch, so without that band functioning you would have second gear (as when you are climbing) but on overrun it would freewheel, so no engine braking effect.
jcl is offline   Reply With Quote
Old 02-16-2018, 05:24 PM   #56
Rivet Master
 
Keyair's Avatar

 
1984 34.5' Airstream 345
Foothill Ranch , California
Join Date: Mar 2010
Posts: 4,288
Images: 1
There ya go!!!!
Thanks for the input!
__________________

__________________
My name is Steve.... and I am an Alumaholic!
Working in my Garage is like playing TETRIS with Tools!
Keyair is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Downhill speed control Vitaver On The Road... 27 10-18-2016 08:26 PM
Downhill Engine Braking Longboard6 Towing, Tow Vehicles & Hitches 4 10-15-2016 02:34 PM
"It" rolls downhill...(too soon old, too late impulsive) Foiled Again Trailer Values 9 08-27-2015 09:52 PM
Riding Shotgun after 40 years of driving safari57 Our Community 29 08-07-2006 09:52 PM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:43 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.