Wanderlodge Owners Group  
BuyByeBlueBird.com
Eclipse
WOG YouTube

Go Back   Wanderlodge Owners Group > Mechanic's Corner > Generators

Generators In this forum we will try to answer any of your questions about the different model generators that can be found on Blue Bird coach's.

Site Search:
Reply
 
Thread Tools
  #1  
Old 08-05-2021
mose mose is offline
Senior Member
 
Join Date: Jul 2016
Location: Aloha
Posts: 1,085
Default PowerTech & Kubota & doghouse modifications

It all started with a leaking coolant hose between the Kubota and radiator that needed replacement. Ended up pulling the generator, replacing the rear PowerTech bearing, and cleaning up the doghouse.

So I'm posting details of some of the other modifications and repairs I performed in the process as it may be useful to someone else...

General comments:
  • Easiest to remove the entire slide with gen/engine still mounted. Hooking the rear engine eyelet is a good balance point. (I actually pulled the gen off the slide since I had removed the isolators so I could order new ones. This made it more difficult.)
  • Removing all underside hose/conduit mounts allows unit to slide out far enough to access all water hoses and electrical connections from the front. Otherwise the hoses and wiring can be removed from the backside if you're small and nimble.
  • Didn't want to cut all splices in the rear electrical box, so removed rear Gen cover and unbolted all wires from the gen connection panel. Removed conduit fitting and pulled box and wires off the back of the slide. Used a burr-bit to enlarge hole for conduit fitting. (Don't forget to disconnect batteries and shut of converters/chargers!)
  • Other than fuel lines and wiring, the only thing holding the slide in is the actuator. Removal of the hitch pin in the front allows the entire slide to be removed.

To be continued...
__________________
Mose Wahlstrom
Aloha, Oregon
1991 WB40 "Dave"
Reply With Quote
  #2  
Old 08-05-2021
mose mose is offline
Senior Member
 
Join Date: Jul 2016
Location: Aloha
Posts: 1,085
Default

First step was cleaning up the doghouse:

- I didn't like how the battery and fuel lines were all tangled/clustered against the side of the generator. I'd had problems with them catching as it motored in/out. Some of this could have been due to prior work.
- Doghouse was lines with 3/4" plywood secured with a few screws that were easy to find once foam was scraped off. Outer layer of doghouse is sheet metal secured with a few screws into the channels on the underside of the floor. Roof of doghouse is isolated from sides/bottom, possibly for vibration isolation as entire generator hangs from frame rails only.
- It appeared that since the Racor was optional, they just drilled some holes and added a fuel loop from inside of the doghouse. I chose to relocate the fuel lines and battery cables to inside the frame rail so that the Racor loop was no longer in the doghouse. Just required punching 2 holes in the frame rail and remaking one copper line to the Racor.
- Insulation was replaced with Randy's favorite duct board. 1" all the way around. Could add 2" on top if desired. Taped the edges.
- Made removable panel to cover the Front brake and parking valve. Should help with noise, heat and airflow. If needed could be accessed from rear of doghouse by removing the final rear blower insulation panel and hiring contortionist.
- The rear doghouse panel was mounted too close to the back of the gen access panel and blocked the louvers. So I moved it back about 2". Just had 3 screws attaching it to the top.
- Duct board was attached with a few large 'insulation' washers; no adhesive.

To be continued...
Attached Thumbnails
Click image for larger version

Name:	doghouse before.jpg
Views:	80
Size:	79.7 KB
ID:	76458   Click image for larger version

Name:	lines before.jpg
Views:	82
Size:	111.3 KB
ID:	76459   Click image for larger version

Name:	lines rerouted.jpg
Views:	77
Size:	157.1 KB
ID:	76460   Click image for larger version

Name:	lines after.jpg
Views:	82
Size:	139.0 KB
ID:	76461   Click image for larger version

Name:	valve access.jpg
Views:	80
Size:	83.5 KB
ID:	76462  
__________________
Mose Wahlstrom
Aloha, Oregon
1991 WB40 "Dave"
Reply With Quote
  #3  
Old 08-05-2021
mose mose is offline
Senior Member
 
Join Date: Jul 2016
Location: Aloha
Posts: 1,085
Default

The vibration isolators were in bad shape. The front had collapsed to the point where the engine mounts were touching the bolt heads. Probably explains why the whole bus would bang/shudder when the generator was shut off. The rears still looked ok.

The factory mounts were 225# on the front and 250# on the rear. Seemed reasonable since the whole unit is probably about 900#. Since the fronts appeared overloaded, I ordered 275# units for all 4 corners. This will slightly raise the spring rates, raise the natural frequency, and may slightly reduce the isolation of 30hz vibration. It did solve the shudder/bang on shutdown.

The front isolators were also grossly misaligned. It appears that a spacer plate was added to prevent the motor mount from pinching the oil pan, however the holes/mounts were not moved accordingly. (When the plate was removed, the mount holes aligned perfectly.) This led to a high side load on the isolators which is evident in their condition. I just slotted the mount holes to allow all isolators to be mounted in a 'free' state.

Got the isolators from Tech Products and they were only $11 each ($16 each shipped). Way cheaper than the ones from PowerTech, etc. PN 61591-4. www.novibes.com

To be continued...
Attached Thumbnails
Click image for larger version

Name:	isolators.jpg
Views:	80
Size:	95.8 KB
ID:	76463   Click image for larger version

Name:	mount spacer.jpg
Views:	73
Size:	196.0 KB
ID:	76464   Click image for larger version

Name:	isolator mount.jpg
Views:	71
Size:	174.8 KB
ID:	76465  
__________________
Mose Wahlstrom
Aloha, Oregon
1991 WB40 "Dave"

Last edited by mose; 08-05-2021 at 12:08 PM. Reason: added isolator part number
Reply With Quote
  #4  
Old 08-05-2021
mose mose is offline
Senior Member
 
Join Date: Jul 2016
Location: Aloha
Posts: 1,085
Default

Replacing the rear gen bearing was pretty straight forward except that the housing was loose where the outer race seated. Attached is pic showing bearing part number.

To 'fix' the housing...

I first checked the rotor gap with a dry fit on the bearing. It was ~10thou larger at the top than the bottom. Then I peened the housing to center the rotor gap (as well as firm up the press fit). Then installed with bearing retainer compound.

Exciter gap was checked as well and was well centered; no mods needed.

If removal is ever needed, bearing will likely pull of rotor rather than out of housing. Then heat can be used to soften retainer compound to remove bearing from housing.

To be continued...
Attached Thumbnails
Click image for larger version

Name:	bearing.jpg
Views:	62
Size:	132.0 KB
ID:	76466   Click image for larger version

Name:	rotor gap.jpg
Views:	61
Size:	175.0 KB
ID:	76467   Click image for larger version

Name:	retaining.jpg
Views:	58
Size:	149.2 KB
ID:	76468   Click image for larger version

Name:	exciter gap.jpg
Views:	63
Size:	198.8 KB
ID:	76469  
__________________
Mose Wahlstrom
Aloha, Oregon
1991 WB40 "Dave"
Reply With Quote
  #5  
Old 08-05-2021
Dieselbird01's Avatar
Dieselbird01 Dieselbird01 is offline
John Wyatt – Administrator/Moderator
 
Join Date: Feb 2008
Location: Titusville
Posts: 5,644
Default

Thanks Mose, excellent writeup - keep going!
__________________
John Wyatt
Titusville, Florida
1991 40' WLWB-WTB 8V92
Body Number F095567
My Location: http://www.bbirdmaps.com/user1.cfm?user=4

1991 40' WB ...From 2008 - Present
1984 ½ PT-36 .From 2000 - 2008
1973 FC-31 .....From 1991 - 2001

Reply With Quote
  #6  
Old 08-05-2021
mose mose is offline
Senior Member
 
Join Date: Jul 2016
Location: Aloha
Posts: 1,085
Default

I also added a 'prime' feature to the generator control. The goal was to allow running of the fuel pump(s) prior to starting the generator. Rather than adding separate control, I just tied it in to the pre-heat function. I see no reason not to prime any time preheat is running. (however probably shouldn't prime for more than about 20s at a time since the glow plugs are heated at the same time.)

This can be accomplished with either diodes or a relay. I chose a relay since the existing breaker would get overloaded with the glow plugs and two fuel pumps (which are normally powered through the oil pressure switch). I also added a separate breaker for the prime feature so it is isolated from the existing controls.

First schematic shows the modifications to add the prime relay. Second schematic represents the current control wiring.

I also modified the schematic to more closely match the reality of the control wiring:
  • Added additional Racor fuel pump.
  • Added wiring for remote gen control switches as well as the remote gen indicator light.
  • Corrected/clarified fuel solenoid wiring for Pull and Hold.
To be continued...
Attached Thumbnails
Click image for larger version

Name:	control mod.jpg
Views:	49
Size:	196.1 KB
ID:	76470   Click image for larger version

Name:	generator schematic add prime.jpg
Views:	46
Size:	178.2 KB
ID:	76471   Click image for larger version

Name:	generator schematic mod.jpg
Views:	42
Size:	176.9 KB
ID:	76472  
__________________
Mose Wahlstrom
Aloha, Oregon
1991 WB40 "Dave"
Reply With Quote
  #7  
Old 08-05-2021
mose mose is offline
Senior Member
 
Join Date: Jul 2016
Location: Aloha
Posts: 1,085
Default

Other modifications:
  • Refreshed linear actuator. Polished commutator, replaced grease, oiled motor bushings, added zerk so screw could be greased.
  • Added elbow fittings to radiator hoses. The 1" wire-inserted hose is quite stiff, and without these elbows, the hose hung way down, risking peril.
  • Telescoping exhaust tube was poorly aligned and couldn't be fixed without modifying the support bracket. Added some length, then loosened all clamps/bolts and retightened after gen tray was fully retracted.
  • Found proper water pump idler pulley that works with factory metric step bolt and metric belt.
  • Added rigid pipe to water outlet. This isn't a performance issue, but allowed both 1" water lines on tray to be made from (1) 10' 'stick' of hose. Saves quite a bit of money since each stick is ~$100.
  • Added regulator access plate to outside of gen box. This allows easy access to replace or adjust the regulator with the gen extended out the nose of the bus.
  • The tray rollers are greaseable with a needle fitting on the grease gun. Lateral rollers were just surface greased.

Hope all that helps somebody.
Attached Thumbnails
Click image for larger version

Name:	actuator zerk.jpg
Views:	62
Size:	73.8 KB
ID:	76473   Click image for larger version

Name:	elbows.jpg
Views:	59
Size:	94.5 KB
ID:	76474   Click image for larger version

Name:	exhaust support.jpg
Views:	63
Size:	174.2 KB
ID:	76475   Click image for larger version

Name:	idler pulley.jpg
Views:	54
Size:	136.0 KB
ID:	76476   Click image for larger version

Name:	pipe.jpg
Views:	61
Size:	199.9 KB
ID:	76477   Click image for larger version

Name:	regulator.jpg
Views:	57
Size:	96.8 KB
ID:	76478   Click image for larger version

Name:	rollers.jpg
Views:	60
Size:	88.6 KB
ID:	76479  
__________________
Mose Wahlstrom
Aloha, Oregon
1991 WB40 "Dave"
Reply With Quote
  #8  
Old 08-05-2021
Randy Dupree's Avatar
Randy Dupree Randy Dupree is offline
Forum owner
 
Join Date: Dec 2007
Location: Port St Joe,Fl
Posts: 46,073
Default

I think it already has a prime feature built into the glow plug switch.
__________________
DO NOT SEND PM
email me at randy@randydupree.com only.

Randy Dupree
2000 LXI 43
Bainbridge,Ga.
Port St Joe Fl.
www.buybyebluebird.com

randy@randydupree.com
Reply With Quote
  #9  
Old 08-05-2021
mose mose is offline
Senior Member
 
Join Date: Jul 2016
Location: Aloha
Posts: 1,085
Default

Quote:
Originally Posted by Randy Dupree View Post
I think it already has a prime feature built into the glow plug switch.
My '91 didn't. But I've seen other schematics that show the diodes and maybe most of them already have the feature.
__________________
Mose Wahlstrom
Aloha, Oregon
1991 WB40 "Dave"
Reply With Quote
  #10  
Old 08-05-2021
CrashTestDummy's Avatar
CrashTestDummy CrashTestDummy is offline
Senior Member
 
Join Date: Aug 2018
Location: Pearland
Posts: 1,014
Default

I think I’d opt for aluminum 90-deg barb or stainless elbow fittings there. That hose IS stiff, and a few heat cycles/hours of engine vibrations/years, will weaken those plastic things.

Nice work, though, sir. Thank you for sharing and documenting.
__________________
Barbara and Gene Beaird
Pearland, Texas
1980 FC35 3208NA
Reply With Quote
Reply

Bookmarks

Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
kubota/powertech fuel leak atckip Generators 5 04-16-2020 09:03 PM
Powertech /kubota question jimmylee Generators 10 08-30-2019 07:25 PM
Powertech w/kubota v1305 LeRoy Generators 20 06-19-2019 12:14 AM
PowerTech Kubota starter? jcs707 Generators 3 07-10-2015 09:15 PM
FC / Kubota Powertech Transplant Version 2.0 iamflagman 'Bird Projects & Modifications 8 07-18-2011 05:15 PM

Web Search:

All times are GMT -4. The time now is 01:15 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.